CN117742096A

CN117742096A - Toner for developing electrostatic latent image, electrostatic latent image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Info

Publication number: CN117742096A
Application number: CN202310292613.6A
Authority: CN
Inventors: 荒井聡一郎; 鹤见洋介; 鸟居靖子
Original assignee: Fujifilm Business Innovation Corp
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2022-09-22
Filing date: 2023-03-23
Publication date: 2024-03-22
Also published as: US20240118640A1; JP2024046537A; EP4343437A1

Abstract

Toner for developing electrostatic latent image, electrostatic latent image developer, toner cartridge, process cartridge, image forming apparatus, and image forming methodThe image-forming toner contains: toner particles containing a binder resin and resin particles; fatty acid metal salt particles externally added to the toner particles; and silica particles (A) which are externally added to the toner particles and which contain a nitrogen-containing element compound containing molybdenum element and which have a Net strength N of molybdenum element measured by fluorescent X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si Is 0.035 to 0.45 inclusive.

Description

Toner for developing electrostatic latent image, electrostatic latent image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Technical Field

The invention relates to a toner for developing an electrostatic latent image, an electrostatic latent image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

Background

Patent document 1 discloses a toner in which an inorganic compound and a fatty acid metal salt are attached to the surface of a master batch containing a binder resin and a release agent, the inorganic compound contains hydrophobic silica, the free ratio of the fatty acid metal salt is 30% or more and 80% or less, and the content of aggregates after pressurization by centrifugal force is 0.15% by mass or less.

Patent document 2 discloses silica particles containing a quaternary ammonium salt, wherein the pore diameter of the silica particles before cleaning is a maximum value F of the frequency of 2nm or less obtained from the pore distribution curve of the nitrogen adsorption method _BEFORE Maximum value F of frequency of pore diameter of 2nm or less obtained from pore distribution curve obtained by nitrogen adsorption method of silica particles after cleaning _AFTER Ratio F of _BEFORE /F _AFTER Is 0.90 to 1.10, and has a maximum value F _BEFORE And a maximum value F obtained from a pore distribution curve of a nitrogen adsorption method of silica particles obtained by calcining silica particles before cleaning at 600 ℃ and having a pore diameter of 2nm or less _SINTERING Ratio F of _SINTERING /F _BEFORE 5 to 20 inclusive.

Patent document 3 discloses an image bearing member protective agent containing a fatty acid metal salt, an inorganic lubricant, and strontium titanate.

Patent document 4 discloses a toner in which fatty acid metal salt particles, titanium oxide particles or strontium titanate particles, and silica particles are present on the surfaces of toner particles.

Patent document 5 discloses a toner containing toner particles, silica fine particles, and at least one selected from the group consisting of strontium titanate, hydrotalcite compounds, fatty acid metal salts, aluminum oxide, and titanium oxide.

Patent document 6 discloses a toner for developing an electrostatic latent image, which contains toner particles, strontium titanate particles a and strontium titanate particles B having different average primary particle diameters, wherein the average primary particle diameter of the strontium titanate particles B is 10nm or more and 100nm or less, and the average primary particle diameter Da of the strontium titanate particles a and the average primary particle diameter Db of the strontium titanate particles B satisfy a relationship of 10.ltoreq.da/db.ltoreq.100.

Patent document 7 discloses a toner for developing an electrostatic latent image, which contains colored resin particles containing a binder resin and a colorant, and an external additive containing core-shell resin particles having a number average primary particle diameter of 10 to 500nm, inorganic particles a having a number average primary particle diameter of 30 to 300nm, and inorganic particles B having a number average primary particle diameter of 6 to 29nm, each of which contains a resin as a condensate of a compound having 2 or more amino groups and formaldehyde in a shell layer.

Patent document 8 discloses a toner for developing an electrostatic latent image, which contains toner particles containing a binder resin containing an amorphous resin and a crystalline resin, wherein when a dynamic viscoelasticity strain dispersion measurement is performed under conditions of a temperature of 130 ℃, a frequency of 1Hz and a strain amplitude of 1.0% to 500%, the integral value of stress in a stress-strain curve at a strain amplitude of 100% exceeds 0Pa and is 350000Pa or less, and the slope of the long diameter exceeds 22 ° and is smaller than 90 °.

Patent document 9 discloses a toner for developing an electrostatic latent image, which contains toner particles containing a binder resin containing an amorphous vinyl resin and a crystalline resin, wherein when a dynamic viscoelasticity strain dispersion measurement is performed under conditions of a temperature of 130 ℃, a frequency of 1Hz and a strain amplitude of 1.0% to 500%, the integral value of stress of a stress-strain curve at a strain amplitude of 100% exceeds 0Pa and is 350000Pa or less, and the slope of the long diameter is 0 ° or more and less than 10 °.

Patent document 10 discloses a toner for developing an electrostatic latent image, which contains a binder resin and a releasing agent, wherein the binder resin contains a crystalline resin, and the storage elastic modulus satisfies a specific relationship when measured by changing the strain from 0.01% to 1000% at a frequency of 1Hz and at 150 ℃.

Patent document 11 discloses a toner for developing an electrostatic latent image, which contains a toner base particle containing a binder resin and a releasing agent, and the binder resin contains a crystalline resin, and the value of the loss tangent peak measured from 25 ℃ to 100 ℃ under the conditions of a frequency of 1Hz and a heating rate of 6 ℃/min and the value of the loss tangent peak measured from 25 ℃ to 100 ℃ under the conditions of a frequency of 1Hz and a heating rate of 3 ℃/min satisfy a specific relationship.

Patent document 12 discloses a toner for developing an electrostatic latent image, which contains an amorphous resin, a crystalline resin, a colorant and a releasing agent, and has a change rate of storage elastic modulus G 'of more than 50% and less than 86%, a change rate of loss elastic modulus g″ of more than 50%, and a storage elastic modulus G' of 5×10 in a range of 1% to 50% strain at a temperature of 150 DEG C ² ～3.5×10 ³ Pa·s。

Patent documents 13 and 14 disclose toners for developing electrostatic latent images, which are composed of toner particles containing a binder resin and have a specific structure in an elastic image of a cross section of the toner particles observed by an atomic force microscope.

Patent document 1: japanese patent laid-open No. 2014-178496

Patent document 2: japanese patent application laid-open No. 2021-151944

Patent document 3: japanese patent laid-open publication No. 2017-173623

Patent document 4: japanese patent application laid-open No. 2021-009250

Patent document 5: japanese patent laid-open No. 2020-148929

Patent document 6: japanese patent laid-open No. 2019-168440

Patent document 7: japanese patent laid-open No. 2015-055857

Patent document 8: japanese patent laid-open No. 2020-042122

Patent document 9: japanese patent laid-open No. 2020-042121

Patent document 10: japanese patent laid-open No. 2020-106685

Patent document 11: japanese patent application laid-open No. 2019-144368

Patent document 12: japanese patent laid-open publication No. 2013-160886

Patent document 13: japanese patent laid-open publication No. 2011-237793

Patent document 14: japanese patent laid-open publication No. 2011-237792

Disclosure of Invention

The object of the present invention is to provide a method for measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, compared with the method in which the N of molybdenum element is measured by fluorescent X-ray analysis in silica particles which are externally added to toner particles containing binder resin and resin particles and contain nitrogen element compound containing molybdenum element _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si When the toner is less than 0.035 or more than 0.45, color streaks are less likely to occur.

Means for solving the above problems include the following means.

< 1 > a toner for developing electrostatic latent images, comprising:

toner particles containing a binder resin and resin particles;

fatty acid metal salt particles externally added to the toner particles; and

Silica particles (A) which are externally added to the toner particles and which contain a nitrogen-containing element compound containing a molybdenum element and which have a Net strength N of the molybdenum element measured by fluorescent X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si Is 0.035 to 0.45 inclusive.

< 2 > the toner for developing an electrostatic latent image according to < 1 >, wherein,

the ratio N of the silica particles (A) _Mo /N _Si Is 0.05 to 0.30 inclusive.

< 3 > the toner for electrostatic latent image development according to < 1 > or < 2 >, wherein,

the ratio Dp/Da of the average particle diameter Dp of the resin particles to the average primary particle diameter Da of the silica particles (A) is 0.75 to 15.

< 4 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 3 >, wherein,

the average primary particle diameter of the fatty acid metal salt particles is 0.5 μm or more and 15 μm or less.

< 5 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 3 >, wherein,

the average primary particle diameter of the fatty acid metal salt particles is 5-15 [ mu ] m.

< 6 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 3 >, wherein,

the average primary particle diameter of the fatty acid metal salt particles is 0.5 μm or more and 3 μm or less.

< 7 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 6 >, wherein,

the fatty acid metal salt particles are zinc stearate particles.

< 8 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 7 >, wherein,

the resin particles are crosslinked vinyl resin particles.

< 9 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 8 >, wherein,

the resin particles are styrene (meth) acrylic resin particles.

< 10 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 9 >, further comprising silica particles (B) other than the silica particles (a) externally added to the toner particles.

< 11 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 10 >, further comprising strontium titanate particles externally added to the toner particles.

< 12 > the toner for developing an electrostatic latent image according to < 11 >, wherein,

the strontium titanate particles have an average primary particle diameter of 200nm or more and 2 μm or less.

< 13 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 12 >, wherein,

the surface coating ratio C1 of the toner particles coated with the silica particles (A) is 10% to 60%.

< 14 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 13 >, further comprising silica particles (B) other than the silica particles (A) externally added to the toner particles,

The ratio C1/C2 of the surface coating ratio C1 of the toner particles coated with the silica particles (A) to the surface coating ratio C2 of the silica particles coated with the silica particles (B) having a primary particle diameter of 80nm to 150nm is 0.2 to 1.5.

< 15 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 14 >, wherein,

the amount of the free oil contained in the toner for electrostatic latent image development is 0.01% by mass or more and 0.1% by mass or less of the total amount of the toner for electrostatic latent image development.

< 16 > the toner for developing an electrostatic latent image according to any one of < 1 > to < 15 >, wherein,

the nitrogen-containing element compound containing molybdenum is at least one selected from the group consisting of a quaternary ammonium salt containing molybdenum and a mixture of a quaternary ammonium salt and a metal oxide containing molybdenum.

The toner for developing an electrostatic latent image according to any one of < 1 > to < 16 >, wherein,

the silica particles (a) are silica particles having a coating structure composed of a reaction product of a silane coupling agent and the nitrogen-containing element compound containing molybdenum attached to the coating structure.

< 18 > the toner for developing an electrostatic latent image according to < 17 >, wherein,

the silane coupling agent contains an alkyl trialkoxysilane.

A toner for developing an electrostatic latent image according to any one of < 1 > to < 18 >, wherein,

when the loss tangent tan delta at 90 ℃ and 1% strain is D1 (90), the loss tangent tan delta at 90 ℃ and 50% strain is D50 (90), the loss tangent tan delta at 150 ℃ and 1% strain is D1 (150), and the loss tangent tan delta at 150 ℃ and 50% strain is D50 (150) in the dynamic viscoelasticity measurement of the electrostatic latent image developing toner,

d1 (90), D50 (90), D1 (150) and D50 (150) are respectively more than 0.5 and less than 2.5,

d50 The values of (150) -D1 (150) are less than 1.5,

d50 The value of (90) -D1 (90) is less than 1.0.

< 20 > an electrostatic latent image developer containing the toner for electrostatic latent image development of any one of < 1 > to < 19 >.

< 21 > a toner cartridge containing the toner for developing an electrostatic latent image of any one of < 1 > to < 19 >, and

is attached to and detached from the image forming apparatus.

< 22 > a process cartridge comprising a developing member,

The developing member accommodates < 20 > the electrostatic latent image developer, and develops an electrostatic latent image formed on a surface of the image holding body into a toner image by the electrostatic latent image developer,

the process cartridge is attached to and detached from the image forming apparatus.

An image forming apparatus, comprising:

an image holding body;

a charging member that charges a surface of the image holding body;

an electrostatic latent image forming member that forms an electrostatic latent image on a surface of the charged image holding body;

a developing member that accommodates < 20 > the electrostatic latent image developer and develops an electrostatic latent image formed on a surface of the image holding body into a toner image by the electrostatic latent image developer;

a transfer member that transfers the toner image formed on the surface of the image holding body onto the surface of a recording medium; and

And a fixing member that fixes the toner image transferred onto the surface of the recording medium.

< 24 > an image forming method, comprising:

a charging step of charging the surface of the image holder;

an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged image holding body;

A developing step of developing an electrostatic latent image formed on a surface of the image holder into a toner image by the electrostatic latent image developer < 20 >;

a transfer step of transferring the toner image formed on the surface of the image holder onto the surface of a recording medium; and

And a fixing step of fixing the toner image transferred onto the surface of the recording medium.

Effects of the invention

According to the invention of < 1 >, < 4 >, < 5 >, < 6 >, < 7 >, < 8 >, < 9 >, < 10 >, < 11 >, < 12 >, < 16 >, < 17 > or < 18 >, there is provided a method for measuring the Net strength N of a molybdenum element by fluorescent X-ray analysis, as compared with the case of a method in which a nitrogen element compound is added to a silica particle containing a binder resin and a toner particle and containing a molybdenum element, in which a nitrogen element compound is contained in a silica particle containing a binder resin and a toner particle _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si When the toner is less than 0.035 or more than 0.45, color streaks are less likely to occur.

According to the invention related to < 2 >, a method for comparing with the ratio N is provided _Mo /N _Si When the content is less than 0.05 or exceeds 0.30, color streaks are not easily generatedIs used for developing electrostatic latent images.

According to the invention of < 3 > there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks when the ratio Dp/Da of the average particle diameter Dp of the resin particles to the average primary particle diameter Da of the silica particles (A) is less than 0.75 or more than 15.

According to the invention of < 13 >, there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the surface coating ratio C1 is less than 10% or more than 60%.

According to the invention of < 14 > there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the ratio C1/C2 of the surface coating ratio C1 to the surface coating ratio C2 is less than 0.2 or exceeds 1.5.

According to the invention of < 15 > there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the amount of free oil contained in the toner for developing an electrostatic latent image is less than 0.01 mass% or more than 0.1 mass%.

According to the invention of < 19 > there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when at least one of D1 (90), D50 (90), D1 (150) and D50 (150) is less than 0.5 or exceeds 2.5, the value of D50 (150) -D1 (150) is 1.5 or more, or the value of D50 (90) -D1 (90) is 1.0 or more.

According to the invention of < 20 >, there is provided a method for producing a toner comprising a binder resin and resin particles, wherein the method comprises the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method comprising the step of measuring the Net strength N of molybdenum element in silica particles containing nitrogen element compound containing molybdenum element and externally added to toner particles containing binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of less than 0.035 or more than 0.45, the development of an electrostatic latent image developer which is less likely to produce color streaks.

According to the invention of < 21 >, there is provided a molybdenum element measured by fluorescent X-ray analysis as compared with silica particles containing a nitrogen-containing element compound containing molybdenum element externally added to toner particles containing a binder resin and resin particlesNet strength N of element _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of less than 0.035 or more than 0.45, color streaks are not easily generated.

According to the invention of < 22 >, there is provided a method for producing a fluorescent powder comprising the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method which is applied to silica particles containing nitrogen element compound containing molybdenum element and externally added to toner particles containing binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of an electrostatic latent image developer of less than 0.035 or more than 0.45, color streaks are less likely to occur.

According to the invention of < 23 >, there is provided a method for producing a fluorescent X-ray-analyzed fluorescent toner containing a nitrogen-containing compound containing a molybdenum element, wherein the fluorescent X-ray-analyzed fluorescent toner containing a nitrogen-containing compound containing a molybdenum element is used as a binder resin and a toner containing a resin particle _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of the electrostatic latent image developer smaller than 0.035 or exceeding 0.45, color streaks are less likely to occur.

According to the invention of < 24 >, there is provided a method for producing a fluorescent X-ray-analyzed fluorescent toner containing a nitrogen-containing compound containing a molybdenum element, wherein the fluorescent X-ray-analyzed fluorescent toner containing a nitrogen-containing compound containing a molybdenum element is used as a binder resin and a toner containing a resin particle _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of an electrostatic latent image developer of less than 0.035 or more than 0.45, color streaks are less likely to occur.

Drawings

Embodiments of the present invention will be described in detail with reference to the following drawings.

Fig. 1 is a schematic configuration diagram showing an example of an image forming apparatus according to the present embodiment;

Fig. 2 is a schematic configuration diagram showing an example of a process cartridge to be attached to and detached from the image forming apparatus according to the present embodiment.

Symbol description

1Y, 1M, 1C, 1K-photoreceptors (an example of an image holding member), 2Y, 2M, 2C, 2K-charging rollers (an example of a charging member), 3-exposing devices (an example of an electrostatic latent image forming member), 3Y, 3M, 3C, 3K-laser beams, 4Y, 4M, 4C, 4K-developing devices (an example of a developing member), 5Y, 5M, 5C, 5K-primary transfer rollers (an example of a primary transfer member), 6Y, 6M, 6C, 6K-photoreceptor cleaning devices (an example of a cleaning member), 8Y, 8M, 8C, 8K-toner cartridges, 10Y, 10M, 10C, 10K-image forming units, 20-intermediate transfer belt (an example of an intermediate transfer member), 22-driving roller, 24-backup roller, 26-secondary transfer roller (one example of secondary transfer member), 28-fixing device (one example of fixing member), 30-intermediate transfer body cleaning device, P-recording paper (one example of recording medium), 107-photoreceptor (one example of image holder), 108-charging roller (one example of charging member), 109-exposure device (one example of electrostatic latent image forming member), 111-developing device (one example of developing member), 112-transfer device (one example of transfer member), 113-photoreceptor cleaning device (one example of cleaning member), 115-fixing device (one example of fixing member), 116-mounting rail, 117-housing, 118-opening portion for exposure, 200-process cartridge, 300-recording paper (an example of recording medium).

Detailed Description

Hereinafter, embodiments of the present invention will be described. These descriptions and examples are provided to illustrate embodiments and do not limit the scope of the embodiments.

In the present invention, the numerical range indicated by "to" is meant to include the numerical values before and after "to" as the minimum value and the maximum value, respectively.

In the numerical ranges described in the present invention in stages, the upper limit or the lower limit described in one numerical range may be replaced with the upper limit or the lower limit of the numerical range described in another stage. In the numerical ranges described in the present invention, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.

In the present invention, the term "process" includes not only an independent process but also a process which is not clearly distinguished from other processes, if the object of the process can be achieved.

In the present invention, the embodiments are described with reference to the drawings, but the configuration of the embodiments is not limited to the configuration shown in the drawings. The sizes of the components in the drawings are conceptual, and the relative relationship between the sizes of the components is not limited thereto.

In the present invention, each component may contain a plurality of corresponding substances. In the present invention, when the amounts of the components in the composition are mentioned, the presence of a plurality of substances corresponding to the components in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified.

In the present invention, a plurality of particles corresponding to each component may be contained. When a plurality of particles corresponding to each component are present in the composition, unless otherwise specified, the particle size of each component indicates a value regarding a mixture of the plurality of particles present in the composition.

In the present invention, "(meth) acrylic acid" is a expression including both acrylic acid and methacrylic acid, and "(meth) acrylate" is a expression including both acrylate and methacrylate.

In the present invention, the "toner for developing an electrostatic latent image" is also referred to as "toner", the "developer for developing an electrostatic latent image" is also referred to as "developer", and the "carrier for developing an electrostatic latent image" is also referred to as "carrier".

Toner for developing electrostatic latent image

The toner according to the present embodiment includes: toner particles containing a binder resin and resin particles; fatty acid metal salt particles externally added to the toner particles; and silica particles (A) externally added to the toner particles. The silica particles (A) are a nitrogen-containing compound containing a molybdenum element and have a Net strength N of the molybdenum element measured by fluorescent X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si Silica particles of 0.035 to 0.45 inclusive.

The image formation using the toner according to the present embodiment is less likely to generate color streaks caused by the unstable posture of the image holder cleaning blade. The mechanism is presumed to be as follows.

Conventionally, there is known a toner in which resin particles are internally added to toner particles in order to suppress deformation of the toner particles or embedding of external additives into the toner particles. If the thermal characteristics of the resin particles contained in the toner particles are such that they are melted by heating and pressurizing at the time of image fixing, the image fixing is not hindered.

However, when the temperature and/or humidity change, the hardness of the toner particle surface of the toner containing toner particles containing resin particles suitable for image fixation changes, and fatty acid metal salt particles as external additives having relatively large particle diameters tend to be released. As a result, fatty acid metal salt particles are excessively supplied to the image holder (i.e., the photoconductor), resulting in a decrease in the coefficient of friction between the image holder and the cleaning blade, which may cause the posture of the cleaning blade to become unstable, and color streaks may be generated on the surface of the image holder and in the image.

Therefore, in order to suppress the above, the toner according to the present embodiment contains, as an external additive, silica particles (a) having a nitrogen-containing element compound containing molybdenum element and having a specific ratio of N _Mo /N _Si Is 0.035 to 0.45 inclusive.

Silica particles (A) passing ratio N _Mo /N _Si The electrostatic charge is 0.035 to 0.45, and the fatty acid metal salt particles are attracted.

On the other hand, with respect to toner particles containing resin particles, the toner particle surfaces are not in a uniformly charged state due to the difference in charging characteristics between the resin particles and the binder resin, but a minute difference in charging is distributed on the toner particle surfaces. Therefore, the silica particles (a) are effectively electrostatically fixed to the surfaces of the toner particles containing the resin particles.

Therefore, it is presumed that the fatty acid metal salt particles are fixed to the toner particles via the silica particles (a), and excessive release of the fatty acid metal salt particles and excessive supply to the image holder can be suppressed. As a result, it is presumed that the image formation using the toner according to the present embodiment is less likely to generate color streaks due to the unstable posture of the image holder cleaning blade.

In the present embodiment, the ratio N of the silica particles (a) _Mo /N _Si Is 0.035 to 0.45 inclusive.

If ratio N _Mo /N _Si If the amount of the silicon dioxide particles is less than 0.035, the inhibition of polarization by the molybdenum atoms does not act against polarization originating from the nitrogen atoms, and the silicon dioxide particles are firmly electrostatically fixed to the toner particle surfaces, and the attraction to the aliphatic metal salt tends to become too strong. In addition, the affinity of the silica particles itself with water increases, and thus the silica particles are easily and largely affected by humidity. As a result, the electrostatic fixing effect becomes uneven, and the stable effect is not easily exhibited. From the viewpoint of suppressing this, the ratio N _Mo /N _Si The content is, for example, preferably 0.035 or more, more preferably 0.05 or more, still more preferably 0.07 or more, and still more preferably 0.10 or more.

If ratio N _Mo /N _Si If the amount of the metal salt exceeds 0.45, the polarization of the nitrogen atom is greatly suppressed by the molybdenum atom, and the silica particles are not easily electrostatically fixed to the toner particle surface, and the attraction to the aliphatic metal salt becomes weak, so that the effect of suppressing color streaks is not easily exhibited. From the viewpoint of suppressing this, the ratio N _Mo /N _Si The content is, for example, 0.45 or less, preferably 0.40 or less, more preferably 0.35 or less, and even more preferably 0.30 or less.

Hereinafter, the composition, structure, and manufacturing method of the toner according to the present embodiment will be described.

[ toner particles ]

The toner particles contain at least a binder resin and resin particles. The toner particles may also contain colorants, mold release agents, and other additives. The toner particles are preferably negatively chargeable, for example.

Binding resin-

Examples of the binder resin include vinyl resins composed of homopolymers of monomers such as styrenes (e.g., styrene, p-chlorostyrene, α -methylstyrene, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), or copolymers of two or more of these monomers.

Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these resins with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers under the coexistence of these resins.

These binder resins may be used singly or in combination of two or more.

The binder resin preferably contains, for example, a polyester resin.

If the binder resin is a polyester resin, when the resin particles contained in the toner particles are styrene (meth) acrylic resin particles, for example, it is easy to control the difference between the SP value of the resin particles (i.e., styrene (meth) acrylic resin particles) and the SP value of the binder resin within a preferable numerical range. Thus, the resin particles (i.e., styrene (meth) acrylic resin particles) are easily dispersed in the toner particles.

The binder resin preferably contains, for example, a polyester resin.

If the binder resin is a polyester resin, the difference in charge between the toner particles and the resin particles becomes appropriate, and the silica particles (a) are easily fixed electrostatically to the toner particle surfaces. Thus, the effect of suppressing excessive release of the fatty acid metal salt via the silica particles (a) can be stably obtained.

The binder resin preferably contains, for example, a polyester resin having an aliphatic dicarboxylic acid unit (i.e., a structural unit derived from an aliphatic dicarboxylic acid).

If the binder resin contains a polyester resin having an aliphatic dicarboxylic acid unit, the resin particles can be dispersed in the toner particles in a more nearly uniform state by increasing the flexibility of the binder resin, and the variation range of the loss tangent tan δ described later can be further reduced, as compared with the case where the binder resin does not contain a polyester resin having an aliphatic dicarboxylic acid unit but contains a polyester resin having only an aromatic dicarboxylic acid unit.

The binder resin preferably contains, for example, an amorphous polyester resin having an aliphatic dicarboxylic acid unit and a crystalline polyester resin having an aliphatic dicarboxylic acid unit. If the binder resin contains the amorphous polyester resin and the crystalline polyester resin, the resin particles can be more uniformly dispersed in the toner particles by the two resins having aliphatic dicarboxylic acid units.

As aliphatic dicarboxylic acids, use may preferably be made, for example, of the general formula "HOOC- (CH) ₂ ) _n -COOH "represents a saturated aliphatic dicarboxylic acid. N in the above general formula is, for example, an integer of preferably 4 to 20, more preferably an integer of 4 to 12.

The binder resin preferably contains, for example, a crystalline resin and an amorphous resin.

The crystalline resin is a resin that exhibits a clear endothermic peak in Differential Scanning Calorimetry (DSC) rather than a stepwise endothermic change. The amorphous resin is a resin that exhibits a stepwise endothermic change in Differential Scanning Calorimetry (DSC) and does not exhibit a clear endothermic peak.

Specifically, the crystalline resin means a resin having a half width of an endothermic peak of 10 ℃ or less when measured at a temperature rising rate of 10 ℃/min, and the amorphous resin means a resin having a half width exceeding 10 ℃ or a resin in which a clear endothermic peak cannot be confirmed.

Crystalline resin-

Examples of the crystalline resin include crystalline polyester resins and crystalline vinyl resins (e.g., polyalkylene resins, long-chain (meth) acrylic acid alkyl ester resins, etc.). From the viewpoints of mechanical strength and low-temperature fixability of the toner, for example, crystalline polyester resins are preferable.

Crystalline polyester resin

Examples of the crystalline polyester resin include polycondensates of polycarboxylic acids and polyols. As the crystalline polyester resin, a commercially available product or a synthetic resin can be used.

From the viewpoint of easy formation of a crystal structure, the crystalline polyester resin is preferably a polycondensate using a linear aliphatic polymerizable monomer, for example, rather than a polycondensate using a polymerizable monomer having an aromatic ring.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1, 9-nonanedicarboxylic acid, 1, 10-decanedicarboxylic acid, 1, 12-dodecanedicarboxylic acid, 1, 14-tetradecanedicarboxylic acid, 1, 18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (for example, dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2, 6-dicarboxylic acid, etc.), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.

The polycarboxylic acid may be used together with the dicarboxylic acid as a carboxylic acid having 3 or more members capable of forming a crosslinked structure or a branched structure. Examples of the 3-membered carboxylic acid include aromatic carboxylic acids (for example, 1,2, 3-benzenetricarboxylic acid, 1,2, 4-naphthalenetricarboxylic acid, etc.), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.

As the polycarboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an olefinic double bond may be used together with the dicarboxylic acid.

The polycarboxylic acid may be used singly or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (for example, linear aliphatic diols having 7 to 20 carbon atoms in the main chain). Examples of the aliphatic diol include ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, 1, 11-undecanediol, 1, 12-dodecanediol, 1, 13-tridecanediol, 1, 14-tetradecanediol, 1, 18-octadecanediol, and 1, 14-docosanediol. Among them, preferred aliphatic diols are, for example, 1, 8-octanediol, 1, 9-nonanediol, and 1, 10-decanediol.

The polyhydric alcohol may be used together with a glycol as a 3-or more-membered alcohol which can form a crosslinked structure or a branched structure. Examples of the 3-or more-membered alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and the like.

The polyhydric alcohol may be used singly or in combination of two or more.

The polyol preferably contains, for example, an aliphatic diol. The proportion of the aliphatic diol in the polyol is, for example, preferably 80 mol% or more, and more preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is, for example, preferably 50 ℃ to 100 ℃, more preferably 55 ℃ to 90 ℃, and still more preferably 60 ℃ to 85 ℃.

The melting temperature of the crystalline polyester resin was determined from a Differential Scanning Calorimeter (DSC) curve obtained by "melting peak temperature" described in the method for determining melting temperature of "method for measuring transition temperature of plastics" of JIS K7121-1987.

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6000 to 35000, for example.

When the toner particles contain a crystalline resin, the proportion of the crystalline resin in the binder resin is, for example, preferably 4% by mass or more and 50% by mass or less, more preferably 6% by mass or more and 30% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

When the toner particles contain the crystalline polyester resin, the proportion of the crystalline polyester resin in the binder resin is, for example, preferably 4% by mass or more and 50% by mass or less, more preferably 6% by mass or more and 30% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

When the mass ratio of the crystalline resin or the crystalline polyester resin in the binder resin is within the above range, it is possible to suppress the penetration of the external additive into the toner particles (1) and to suppress the difference in glossiness of the fixed image due to the fixing conditions (difference in temperature and pressure) as compared with the case where the mass ratio is less than the above range and the case where the mass ratio is more than the above range, (2) and to achieve both the storage stability of the toner and good fixability.

Amorphous resin

Examples of the amorphous resin include amorphous polyester resins, amorphous vinyl resins (e.g., styrene acrylic resins, etc.), epoxy resins, polycarbonate resins, polyurethane resins, and the like. Among them, for example, an amorphous polyester resin and an amorphous vinyl resin (particularly, a styrene acrylic resin) are preferable, and an amorphous polyester resin is more preferable.

Amorphous polyester resin

Examples of the amorphous polyester resin include polycondensates of polycarboxylic acids and polyols. As the amorphous polyester resin, commercially available ones may be used, or synthetic resins may be used.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof. Among them, for example, aromatic dicarboxylic acids are preferable as the polycarboxylic acid.

The polycarboxylic acid may be used together with the dicarboxylic acid as a carboxylic acid having 3 or more members capable of forming a crosslinked structure or a branched structure. Examples of the carboxylic acid having 3 or more atoms include trimellitic acid, pyromellitic acid, acid anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.

The polycarboxylic acid may be used singly or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol a, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol a, propylene oxide adducts of bisphenol a, etc.). Among them, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

As the polyol, a polyol having 3 or more members capable of forming a crosslinked structure or a branched structure may be used together with a diol. Examples of the 3-or more-membered polyol include glycerol, trimethylolpropane and pentaerythritol.

The polyhydric alcohol may be used singly or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is, for example, preferably 50 ℃ or higher and 80 ℃ or lower, and more preferably 50 ℃ or higher and 65 ℃ or lower.

The glass transition temperature of the amorphous polyester resin is obtained from a Differential Scanning Calorimetry (DSC) curve, more specifically, from "extrapolated glass transition onset temperature" described in the method for obtaining glass transition temperature "in JIS K7121-1987," method for measuring transition temperature of plastics ".

The weight average molecular weight (Mw) of the amorphous polyester resin is, for example, preferably 5000 to 1000000, more preferably 7000 to 500000.

The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 to 100000, for example.

The molecular weight distribution Mw/Mn of the amorphous polyester resin is, for example, preferably 1.5 to 100, more preferably 2 to 60.

The weight average molecular weight and the number average molecular weight of the amorphous polyester resin were measured by Gel Permeation Chromatography (GPC). In the molecular weight measurement by GPC, GPC/HLC-8120 GPC manufactured by TOSOH CORPORATION was used as a measuring device, column/TSKgel SuperHM-M manufactured by TOSOH CORPORATION (15 cm) was used, and tetrahydrofuran was used as a solvent. The weight average molecular weight and the number average molecular weight were calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample according to the measurement result.

The amorphous polyester resin is obtained by a known production method. Specifically, it is obtained, for example, by the following method: the polymerization temperature is set to 180 ℃ to 230 ℃ both inclusive, and the reaction is carried out while the pressure in the reaction system is reduced as needed to remove water and alcohol generated during condensation.

In the case where the monomers of the raw materials are not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a cosolvent to dissolve them. In this case, the polycondensation reaction is carried out while the cosolvent is distilled off. In the case where a monomer having poor compatibility is present, for example, the monomer having poor compatibility and an acid or alcohol to be polycondensed with the monomer may be condensed in advance and then polycondensed with the main component.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and still more preferably 60% by mass or more and 85% by mass or less, relative to the entire toner particles.

Resin particle-

The resin particles are preferably uniformly contained in, for example, two regions, i.e., a region near the surface of the toner particles (hereinafter, referred to as "surface region") and a region near the center of the toner particles (hereinafter, referred to as "center region"). By containing the resin particles in both the surface region and the center region, compared with the case where the resin particles are contained in only either one of the surface region and the center region, (1) the embedding of the external additive into the toner particles can be suppressed, (2) both the storage stability of the toner and good fixability can be achieved, and (3) the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed.

The average particle diameter of the resin particles (referred to as "average particle diameter Dp" in the present invention) is, for example, preferably 60nm to 300nm, more preferably 100nm to 200nm, still more preferably 130nm to 170 nm.

When the average particle diameter Dp is within the above range, it is possible to (1) suppress the external additive from being buried in the toner particles, (2) achieve both storage stability of the toner and good fixability, and (3) suppress the difference in glossiness of the fixed image due to the fixing conditions (difference in temperature and pressure) as compared with the case where the average particle diameter Dp is smaller than the above range and larger than the above range.

The average particle diameter of the resin particles is a value measured by a Transmission Electron Microscope (TEM). As the transmission electron microscope, JEOL Ltd.

The toner particles were embedded with an epoxy resin, and a microtome was used to prepare a microtome sample of about 0.3 μm. Cross sections of the toner particles were photographed at 4500 times magnification with a transmission electron microscope. 1000 resin particles were randomly selected from the TEM image, and the respective circle equivalent diameters (nm) were obtained, and arithmetic average was performed to obtain the average particle diameter (nm).

In the case of producing toner particles by the aggregate method, the average particle diameter of the resin particles in the toner particles can be controlled according to the average particle diameter of the resin particles contained in the resin particle dispersion. The average particle diameter of the resin particles in the toner particles is substantially equal to the average particle diameter of the resin particles contained in the resin particle dispersion liquid. The average particle diameter of the resin particles contained in the resin particle dispersion is measured by a laser diffraction type particle size distribution measuring apparatus (for example, HORIBA, manufactured by ltd. System, LA-700).

Examples of the resin constituting the resin particles include polyolefin (polyethylene, polypropylene, etc.), styrene resin (polystyrene, α -polymethylstyrene, etc.), a (meth) acrylic resin (polymethyl methacrylate, polyacrylonitrile, etc.), a styrene (meth) acrylic resin, an epoxy resin, a polyurethane resin, a polyurea resin, a polyamide resin, a polycarbonate resin, a polyether resin, a polyester resin, and a copolymer resin thereof. These resins may be used singly or in combination of two or more.

As the resin constituting the resin particles, for example, a polyolefin, a styrene-based resin, a (meth) acrylic resin, a vinyl-based resin such as a styrene (meth) acrylic resin, and the like are preferable, and a styrene (meth) acrylic resin is more preferable. That is, the resin particles are, for example, preferably vinyl resin particles, and more preferably styrene (meth) acrylic resin particles.

The resin particles are preferably, for example, crosslinked resin particles from the viewpoint of appropriately hardening the toner particle surface for the purpose of suppressing the embedding of the external additive. The "crosslinked resin particles" are resin particles containing a resin having a crosslinked structure between atoms. The crosslinked resin is, for example, a crosslinked product of the above resin.

Examples of the crosslinked resin particles include crosslinked resin particles crosslinked by ionic bonds (ionic crosslinked resin particles), crosslinked resin particles crosslinked by covalent bonds (covalent bond crosslinked resin particles), and the like. As the crosslinked resin particles, for example, crosslinked resin particles crosslinked by covalent bonds are preferable.

When the binder resin contains a polyester resin, the crosslinked resin particles are preferably crosslinked vinyl resin particles composed of crosslinked products of vinyl resins, for example, from the viewpoint of appropriately distributing a small charge difference on the surfaces of the toner particles. As the crosslinked vinyl resin, for example, a crosslinked product of a styrene (meth) acrylic resin is preferable. That is, as the crosslinked resin particles, for example, crosslinked styrene (meth) acrylic resin particles are more preferable. The resin particles (S) described later are easily realized by constituting the resin particles from the crosslinked product of a styrene (meth) acrylic resin.

Examples of the styrene (meth) acrylic resin include resins obtained by polymerizing the following styrene monomers and (meth) acrylic monomers by radical polymerization.

Examples of the styrene monomer include styrene, α -methylstyrene and vinylnaphthalene; alkyl-substituted styrenes such as 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, and 4-ethylstyrene; halogen substituted styrenes such as 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.; fluorine-substituted styrenes such as 4-fluorostyrene and 2, 5-difluorostyrene; etc. Styrene and α -methylstyrene are preferable examples of the styrene monomer. The styrene monomer may be used alone or in combination of two or more.

Examples of the (meth) acrylic monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, biphenyl (meth) acrylate, diphenyl (meth) acrylate, t-butylphenyl (meth) acrylate, t-butyl (meth) acrylate, biphenyl (meth) acrylate, cyclohexyl (meth) acrylate, and ethyl (meth) acrylate Diethylaminoethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, acrylonitrile, acrylamide, and the like. The (meth) acrylic monomer may be used singly or in combination of two or more.

As the (meth) acrylic monomer, for example, a combination of a lower alkyl (meth) acrylate and a carboxyl lower alkyl (meth) acrylate is preferable.

In the lower alkyl (meth) acrylate, the "lower alkyl" means a carbon number of 1 to 5, and the "lower alkyl" is preferably a carbon number of 2 to 4, for example, and more preferably a carbon number of 3 or 4. Examples of the lower alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, and neopentyl (meth) acrylate. Among them, for example, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate are preferable, and n-butyl (meth) acrylate is particularly preferable.

In the carboxy lower alkyl (meth) acrylate, "lower alkyl" means a carbon number of 1 to 5, and "lower alkyl" is preferably a carbon number of 2 to 4, for example, and more preferably a carbon number of 2 or 3. Examples of the carboxy lower alkyl (meth) acrylate include 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, and 5-carboxypentyl (meth) acrylate. Among them, for example, 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, and 3-carboxypropyl (meth) acrylate are preferable, and 2-carboxyethyl (meth) acrylate is particularly preferable.

As the (meth) acrylic monomer, for example, a combination of n-butyl (meth) acrylate and 2-carboxyethyl (meth) acrylate is particularly preferable.

The mass ratio of the carboxyl lower alkyl (meth) acrylate to the total amount of the lower alkyl (meth) acrylate and the carboxyl lower alkyl (meth) acrylate is, for example, preferably 0.1 mass% or more and 2.0 mass% or less, more preferably 0.2 mass% or more and 1.0 mass% or less, and still more preferably 0.4 mass% or more and 0.7 mass% or less.

The polymerization ratio (mass basis, styrene monomer, (meth) acrylic monomer) of the styrene monomer to the (meth) acrylic monomer is, for example, preferably 20:80 to 80:20, more preferably 30:70 to 70:30, still more preferably 40:60 to 60:40.

Examples of the crosslinking agent for crosslinking the resin include aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; polyvinyl esters of aromatic polycarboxylic acids such as divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesic acid, trivinyl trimesic acid, divinyl naphthalate and divinyl biphenylcarboxylate; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridine dicarboxylic acid esters; vinyl esters of unsaturated heterocyclic carboxylic acids such as vinyl Jiao Nian acid ester, vinyl furan carboxylic acid ester, vinyl pyrrole-2-carboxylic acid ester and vinyl thiophene carboxylic acid ester; (meth) acrylates of linear polyols such as butanediol di (meth) acrylate, hexanediol di (meth) acrylate, octanediol di (meth) acrylate, nonanediol di (meth) acrylate, decanediol di (meth) acrylate, dodecanediol di (meth) acrylate, and the like; (meth) acrylic esters of branched-chain substituted polyols such as neopentyl glycol dimethacrylate and 2-hydroxy-1, 3-bisacryloyloxypropane; polyethylene glycol di (meth) acrylates, polypropylene polyethylene glycol di (meth) acrylates, divinyl succinate, divinyl fumarate, vinyl maleate, divinyl diglycolate, vinyl itaconate, divinyl acetonate, divinyl glutarate, divinyl 3,3' -thiodipropionate, divinyl trans-aconitate, trivinyl trans-aconitate, divinyl adipate, divinyl pimelate, divinyl suberate, divinyl azelate, divinyl sebacate, divinyl dodecanedioate, divinyl tridecyl, and other polyvinyl esters of polycarboxylic acids; etc. The crosslinking agent may be used alone or in combination of two or more.

As the crosslinking agent for crosslinking the resin, for example, a 2-functional alkyl (meth) acrylate having a long chain alkylene chain having 6 or more carbon atoms is preferable. That is, the crosslinked resin particles preferably have a structural unit derived from a 2-functional alkyl (meth) acrylate, for example, and the number of carbon atoms of the alkylene chain in the structural unit is 6 or more. Similarly, the crosslinked styrene (meth) acrylic resin particles preferably have a structural unit derived from a 2-functional alkyl (meth) acrylate, for example, and the number of carbon atoms of an alkylene chain in the structural unit is 6 or more.

Toners containing toner particles (crosslinked resin particles having a structural unit derived from a 2-functional alkyl (meth) acrylate and having an alkylene chain in the structural unit having 6 or more carbon atoms) are likely to exhibit preferable viscoelastic properties, for example (details will be described later). For example, a toner having preferable viscoelastic properties can suppress the deformation amount of toner particles within a predetermined range even under high-pressure fixing conditions, and thus can suppress the difference in glossiness of an image. However, when the difference in elasticity between the crosslinked resin particles contained in the toner particles and the binder resin is too large, the effect of suppressing the change in loss tangent tan δ by the crosslinked resin particles tends to be less likely to be obtained. Therefore, for example, it is preferable to control the elasticity of the crosslinked resin particles not to be excessively high. If the crosslink density of the crosslinked resin particles is high (i.e., if the distance between the crosslinking points is short), the elasticity of the crosslinked resin particles becomes too high, whereas if the crosslinked resin particles have a structural unit derived from a 2-functional alkyl (meth) acrylate and the number of carbon atoms of the alkylene chain in the structural unit is 6 or more, the crosslink density of the crosslinked resin particles is suitably low (i.e., the distance between the crosslinking points is suitably long), and the elasticity of the crosslinked resin particles does not become too high. As a result, the difference in elasticity between the crosslinked resin particles contained in the toner particles and the binder resin is not excessive, and the effect of suppressing the change in loss tangent tan δ by the crosslinked resin particles can be obtained, whereby the difference in glossiness of the image can be suppressed.

The number of carbon atoms of the alkylene chain in the 2-functional alkyl (meth) acrylate is, for example, preferably 6 or more and 20 or less, more preferably 6 or more and 12 or less, and still more preferably 8 or more and 12 or less, from the viewpoint of adjusting the crosslinking density of the crosslinked resin constituting the crosslinked resin particles within an appropriate range.

Examples of the 2-functional alkyl (meth) acrylate include at least one of 1, 6-hexanediol di (meth) acrylate, 1, 8-octanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, 1, 12-dodecanediol di (meth) acrylate, and the like, preferably 1, 10-decanediol di (meth) acrylate and 1, 10-decanediol di (meth) acrylate.

When the resin particles are polymers containing a composition of a styrene monomer, a (meth) acrylic monomer and a crosslinking agent, the viscoelasticity of the resin particles can be controlled by adjusting the amount of the crosslinking agent contained in the composition. If the amount of the crosslinking agent contained in the composition is increased, the storage elastic modulus G' of the resin particles tends to be increased. The content of the crosslinking agent is, for example, preferably 0.3 parts by mass or more and 5.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the total of the styrene-based monomer, the (meth) acrylic-based monomer, and the crosslinking agent.

The proportion of the resin particles in the entire toner particles is, for example, preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

The proportion of the crosslinked vinyl resin particles in the entire toner particles is, for example, preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

The proportion of the styrene (meth) acrylic resin particles in the entire toner particles is, for example, preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

The proportion of the crosslinked styrene (meth) acrylic resin particles in the entire toner particles is, for example, preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

When the content of the resin particles is 1, the content of the crystalline resin relative to the resin particles contained in the toner particles is, for example, preferably 0.2 to 10, more preferably 1 to 5.

That is, the ratio Mc/Mp of the mass reference of the content Mp of the resin particles contained in the toner particles to the content Mc of the crystalline resin is, for example, preferably 0.2 to 10, more preferably 1 to 5.

If the ratio Mc/Mp is 0.2 or more, the image fixability is good due to the contribution of the crystalline resin, which is a component causing a viscosity decrease in the fixing temperature range.

If the ratio Mc/Mp is 10 or less, the amount of deformation of the toner during fixing can be appropriately suppressed, and the difference in glossiness of the fixed image due to the fixing condition can be suppressed.

When the content of the resin particles is 1, the content of the amorphous resin relative to the resin particles contained in the toner particles is preferably 1.3 or more and 45 or less, more preferably 3 or more and 15 or less, for example.

That is, the ratio Ma/Mp of the mass reference of the content Mp of the resin particles contained in the toner particles to the content Ma of the amorphous resin is preferably 1.3 or more and 45 or less, more preferably 3 or more and 15 or less.

If the mass ratio of the resin particles, the crosslinked vinyl resin particles, the styrene (meth) acrylic resin particles, or the crosslinked styrene (meth) acrylic resin particles is within the above range, the external additive can be suppressed from being buried in the toner particles (1) compared with the case where the external additive is less than the above range and the case where the external additive is more than the above range, (2) the storage stability of the toner and the good fixability can be combined, and (3) the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed.

For example, in the dynamic viscoelasticity measurement in which the temperature is raised at a rate of 2℃per minute, the resin particles preferably have a storage elastic modulus G' of 1X 10 in a range of 90℃to 150 ℃ ⁴ Pa or more and 1×10 ⁶ Pa or less. Hereinafter, the resin particles having the above-described characteristics are referred to as "resin particles (S)".

The storage elastic modulus of the resin particles (S)G' is 1X 10 ⁴ Pa or more and 1×10 ⁶ Pa or less, for example, preferably 1×10 ⁵ Pa or more and 8×10 ⁵ Pa or less, more preferably 1×10 ⁵ Pa or more and 6×10 ⁵ Pa or below.

If the storage elastic modulus G 'of the resin particles (S) is within the above range, (1) the embedding of the external additive into the toner particles can be suppressed, (2) both the storage stability of the toner and good fixability can be achieved, and (3) the difference in glossiness of the fixed image due to the fixing conditions (difference in temperature and pressure) can be suppressed, as compared with the case where the storage elastic modulus G' of the resin particles (S) is smaller than the above range and larger than the above range.

A storage elastic modulus G' of less than 1X 10 ⁴ Pa, the resin particles (S) can suppress the glossiness of the fixed image fixed under high temperature and high pressure conditions. This suppresses the difference in glossiness of the fixed image caused by the fixing condition (difference in temperature and pressure).

The storage modulus of elasticity G' exceeds 1X 10 ⁶ Pa, the resin particles (S) can suppress the decrease in fixability due to the excessively high elasticity of the toner particles, and thus can obtain good fixability.

In the dynamic viscoelasticity measurement in which the temperature is raised at a rate of 2 ℃/min, the resin particles (S) preferably have a loss tangent tan δ of 0.01 to 2.5 in the range of 30 ℃ to 150 ℃. In this case, the resin particles (S) preferably have a loss tangent tan δ of 0.01 to 1.0, more preferably 0.01 to 0.5, in a range of 65 ℃ to 150 ℃.

The loss tangent tan delta of the resin particles (S) in the range of 30 ℃ to 150 ℃ inclusive is in the above range,

(1) Can inhibit the external additive from being buried in the toner particles, (2) can have both storage stability and good fixability of the toner,

(3) It is possible to suppress the difference in glossiness of the fixed image caused by the fixing condition (difference in temperature and pressure).

The loss tangent tan delta of the resin particles (S) in the range of 65 ℃ to 150 ℃ inclusive, which is the temperature at which the toner particles are easily deformed, is in the above range, (1) the embedding of the external additive into the toner particles can be suppressed, (2) both of the storage stability of the toner and good fixability can be achieved, and (3) the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed.

The glass transition temperature Tg of the resin particles (S) is preferably, for example, 10℃to 45 ℃. When the Tg of the resin particles (S) is 10 ℃ or higher and 45 ℃ or lower, better fixability of the toner is achieved, and the difference in glossiness between the fixed image under low-temperature and low-pressure conditions and the fixed image under high-temperature and high-pressure conditions is further reduced. The Tg of the resin particles (S) is, for example, more preferably 15℃or higher and 40℃or lower, and still more preferably 20℃or higher and 35℃or lower.

When the Tg of the resin particles (S) is 10 ℃ or higher, the difference between the glass transition temperature of the resin particles and the glass transition temperature of the binder resin is small, so that the resin particles (S) are not unevenly dispersed at the time of manufacturing the toner particles, and the dispersion uniformity of the resin particles (S) inside the toner particles is improved, whereby the difference in glossiness of the fixed image due to the fixing condition can be suppressed.

When the Tg of the resin particles (S) is 45 ℃ or lower, the melting property of the binder resin is not adversely affected during image fixing, and the low-temperature fixability of the toner is good.

The storage modulus G', loss tangent tan δ and glass transition temperature Tg of the resin particles (S) were determined by the following measurement methods.

The resin particles (S) were molded into a disk shape having a thickness of 2mm and a diameter of 8mm by applying pressure thereto, to thereby prepare a test sample. As a method for removing the resin particles (S) from the toner particles, for example, a method in which the toner particles are immersed in a solvent in which the binder resin is dissolved and the resin particles (S) are not dissolved to recover the resin particles (S) is cited.

The measurement sample was sandwiched between parallel plates having a diameter of 8mm, and the dynamic viscoelasticity was measured by heating the sample from 10℃to 150℃at a rate of 2℃per minute with a gap of 3mm and a frequency of 1Hz and a strain of 0.1% to 100% by using a dynamic viscoelasticity measuring apparatus (Rheometer ARES-G2, manufactured by TA Instruments). The storage elastic modulus G' and the loss tangent tan δ were obtained from the respective curves of the storage elastic modulus and the loss elastic modulus obtained by the measurement. The peak temperature of the loss tangent tan delta was taken as the glass transition temperature Tg.

The resin particles (S) are, for example, preferably crosslinked resin particles, from the viewpoint of controlling the storage elastic modulus G' in the range of 90 ℃ to 150 ℃.

The proportion of the resin particles (S) in the entire toner particles is, for example, preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

When the mass ratio of the resin particles (S) is within the above range, (1) the embedding of the external additive into the toner particles can be suppressed, (2) both the storage stability of the toner and good fixability can be achieved, and (3) the difference in glossiness of the fixed image due to the fixing conditions (difference in temperature and pressure) can be suppressed, as compared with the case where the mass ratio is less than the above range and the case where the mass ratio is more than the above range.

Coloring agent-

Examples of the colorant include pigments such as carbon black, chrome yellow, hansa yellow, benzidine yellow, vat yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, fu Ergan orange, carmine, permanent red, brilliant carmine 3B, brilliant carmine 6B, dupont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, ultramarine blue, copper oil blue, methylene chloride blue, phthalocyanine blue, pigment blue, phthalocyanine green, malachite green oxalate; dyes such as acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo, phthalocyanine, nigrosine, polymethine, triphenylmethane, diphenylmethane, and thiazole; inorganic pigments such as titanium compounds and silica.

The colorant is not limited to a substance having absorption in the visible light region. The colorant may be, for example, a substance having an absorption in the near infrared region, or a fluorescent colorant.

Examples of the colorant having an absorption in the near infrared region include ammonium salt compounds, naphthalocyanine compounds, squaraine compounds, and croconic acid compounds.

As the fluorescent colorant, there may be mentioned the fluorescent colorant described in paragraph 0027 of JP 2021-127431A.

The colorant may be a colorant having a glitter property. Examples of the brightening colorant include metal powders such as aluminum, brass, bronze, nickel, stainless steel, and zinc; mica coated with titanium oxide or iron oxide yellow; a flaky inorganic crystal substrate coated with barium sulfate, a layered silicate, a layered aluminosilicate or the like; single crystal platy titanium oxide, alkaline carbonate, bismuth oxychloride, natural guanine, flaky glass powder and flaky glass powder subjected to metal evaporation; etc.

The colorant may be used alone or in combination of two or more.

The colorant may be used as required, or may be used together with a dispersant.

In the present embodiment, the toner particles may or may not contain a colorant. The toner according to the present embodiment may be a toner (so-called transparent toner) in which toner particles do not contain a colorant.

In this embodiment, even when the toner particles do not contain a colorant, the image formation using the toner according to the embodiment is less likely to cause the posture of the image holder cleaning blade to become unstable.

In the present embodiment, when the toner particles contain a colorant, the content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 15% by mass or less, relative to the entire toner particles.

Mold release agent-

Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice bran wax, candelilla wax, etc.; synthetic or mineral/petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters; etc. The mold release agent is not limited thereto.

The melting temperature of the release agent is, for example, preferably 50 ℃ or more and 110 ℃ or less, more preferably 60 ℃ or more and 100 ℃ or less.

The melting temperature was determined from a Differential Scanning Calorimeter (DSC) curve obtained by "melting peak temperature" described in the method for determining melting temperature of "method for measuring transition temperature of plastics" in JIS K7121-1987.

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, relative to the entire toner particle.

Other additives-

Examples of the other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as internal additives.

[ Structure, composition and Properties of toner particles ]

The toner particles may be toner particles having a single-layer structure or toner particles having a so-called core/shell structure, which are composed of a core (core particle) and a coating layer (shell layer) coating the core.

When the toner particles have a core/shell structure, the toner particles may be in any of a form in which only the core particles contain resin particles, a form in which only the shell layers contain resin particles, and a form in which both the core particles and the shell layers contain resin particles. In the case where the toner particles have a core/shell structure, for example, from the viewpoint of suppressing the embedding of the external additive, it is preferable that the core particles and the shell layer each contain resin particles, and it is more preferable that the core particles and the shell layer each contain resin particles in a highly uniformly dispersed manner.

The toner particles having a core/shell structure include, for example, core particles containing a binder resin, resin particles, a colorant, and a release agent, and shell layers containing a binder resin and resin particles.

The volume average particle diameter (D50 v) of the toner particles is, for example, preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less.

The volume average particle diameter of the toner particles was measured using Coulter Multisizer II (Beckman Coulter, inc.), wherein ISOTON-II (Beckman Coulter, inc.) was used as the electrolyte. To 2ml of a 5 mass% aqueous solution of a surfactant (for example, preferably sodium alkylbenzenesulfonate), a measurement sample of 0.5mg or more and 50mg or less is added, and this is added to 100ml or more and 150ml or less of an electrolyte. The electrolyte solution to which the sample was added was subjected to a dispersion treatment for 1 minute by an ultrasonic disperser, and the particle diameter of the particles was measured in a range of 2 μm to 60 μm by Coulter Multisizer II using pores having a pore diameter of 100 μm. The number of particles to be sampled is 50000. Based on the measured particle size distribution, the volume distribution or the number distribution is plotted on the small diameter side, and the particle size at 50% is taken as the volume average particle size D50v or the number average particle size D50p.

The average circularity of the toner particles is, for example, preferably 0.94 to 1.00, more preferably 0.95 to 0.98.

The average circularity of the toner particles is an average of (circle equivalent circumference)/(circumference) = (circumference of a circle having the same area as the projected area of the particles)/(circumference of the projected image of the particles).

As a particle image measuring apparatus, a flow type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation) was used. The number of samples of toner particles was 3500. When the toner has an external additive, the toner is dispersed in water containing a surfactant, and subjected to ultrasonic treatment to obtain toner particles from which the external additive has been removed.

SP value difference between resin particles and binder resin

The difference (SP value (S) -SP value (R)) between the SP value (in the present invention, referred to as SP value (S)) of the resin particles and the SP value (in the present invention, referred to as SP value (R)) of the binder resin is, for example, preferably-0.32 or more and-0.12 or less, more preferably-0.29 or more and-0.18 or less.

For example, the resin particles are preferably resin particles (S), and the difference between the SP value (S) of the resin particles (S) and the SP value (R) of the binder resin (SP value (S) -SP value (R)) is preferably-0.32 or more and-0.12 or less, more preferably-0.29 or more and-0.18 or less.

When the binder resin is a mixed resin, the SP value of the binder resin having the largest content in terms of mass is defined as the SP value (R).

If the difference (SP value (S) -SP value (R)) is within the above-described range, the resin particles are easily dispersed in a nearly uniform state in the toner particles where affinity of the binder resin constituting most of the toner particles with the resin particles is suitably ensured, as compared with the case where the difference is smaller than the above-described range. Therefore, the toner is liable to have near viscoelasticity at a high temperature and a low strain, and the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed. That is, compared with the case where the difference (SP value (S) -SP value (R)) is smaller than the above range, the following is less likely to occur: the affinity of the binder resin to the resin particles is too high, which causes the resin particles to easily move in the toner particles, partially agglomerating the resin particles, and reducing the effect of the resin particles.

If the difference (SP value (S) -SP value (R)) is within the above range, an excessive mixing or compatibility of the resin particles and the binder resin at the time of melting the toner can be suppressed to cause an increase in the melt viscosity of the toner as a whole, as compared with a case where the difference is larger than the above range. Thus, the decrease in the fixability due to the excessive viscoelasticity can be suppressed, and good fixability can be obtained.

The SP value (S) of the resin particles is, for example, preferably 9.00 to 9.15, more preferably 9.03 to 9.12, and still more preferably 9.06 to 9.10.

The SP value (S) of the resin particles (S) is, for example, preferably 9.00 to 9.15, more preferably 9.03 to 9.12, and still more preferably 9.06 to 9.10.

SP value (S) and SP value (R) are expressed in units of (cal/cm) ³ ) ^1/2 ) Is a solubility parameter calculated by the OKITSU method. Details of the OKITSU method are described in "Journal of the Adhesion Society of Japan, vol.29, no.5 (1993)".

Viscoelastic properties of the component (excluding the component) after removal of the resin particles

Hereinafter, the component from which the resin particles are removed from the toner particles will be referred to as an "excluded component" andup to less than 1X 10 ⁵ The temperature at which the storage elastic modulus G' of Pa is at is called "the specific elastic modulus reaches the temperature".

The other components are preferably those having a storage elastic modulus G' of 1X 10 in the range of 30 ℃ to 50 ℃ in the dynamic viscoelasticity measurement in which the temperature is raised at a rate of 2 ℃/min ⁸ Pa or more, and the specific elastic modulus reaches a temperature of 65 ℃ or more and 90 ℃ or less.

The exception components satisfying the above have a high elastic modulus at low temperature and a low elastic modulus at 65 ℃ or more and 90 ℃ or less. As a result, the toner particles are easily melted by heating, and the fixing property is improved.

The storage modulus G' of the other components is preferably 1X 10 at 30℃to 50℃inclusive ⁸ Pa or more, more preferably 1×10 ⁸ Pa or more and 1×10 ⁹ Pa or less, more preferably 2X 10 ⁸ Pa or more and 6×10 ⁸ Pa or below.

When the storage elastic modulus G ' of the external component is in the above range of 30 ℃ to 50 ℃, the storage stability of the toner and the good fixability can be both achieved, and the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed, compared with the case where the storage elastic modulus G ' is smaller than the above range and the case where the storage elastic modulus G ' is larger than the above range.

The specific elastic modulus of the other components is preferably 65℃or more and 90℃or less, more preferably 68℃or more and 80℃or less, and still more preferably 70℃or more and 75℃or less.

When the specific elastic modulus of the external component reaches a temperature within the above range, the toner storage stability and the good fixability can be achieved at the same time, and the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed, as compared with the case where the specific elastic modulus is lower than the above range and the case where the specific elastic modulus is higher than the above range.

The specific modulus of elasticity of the other components is preferably 0.8 to 1.6, more preferably 0.9 to 1.5, and even more preferably 1.0 to 1.4, inclusive, when the specific modulus reaches the temperature.

When the specific elastic modulus of the external component reaches the loss tangent tan δ at the temperature within the above range, the toner can be stored stably and excellent fixability, and the difference in glossiness of the fixed image due to the fixing condition (difference in temperature and pressure) can be suppressed, as compared with the case where the specific elastic modulus is smaller than the above range and the case where the specific elastic modulus is larger than the above range.

The storage modulus G' and loss tangent tan delta of the other components were determined by the following measurement methods.

Resin particles are removed from toner particles to obtain an exclusive component. The sample for measurement was produced by molding the other components into a tablet shape at ordinary temperature (25 ℃.+ -. 3 ℃) by a compression molding machine. The measurement sample was sandwiched between parallel plates having a diameter of 8mm, and the dynamic viscoelasticity was measured by heating the sample from 30℃to 150℃at a rate of 2℃per minute with a gap of 3mm and a frequency of 1Hz and a strain of 0.1% to 100% by using a dynamic viscoelasticity measuring apparatus (Rheometer ARES-G2, manufactured by TA Instruments). The storage elastic modulus G' and the loss tangent tan δ were obtained from the respective curves of the storage elastic modulus and the loss elastic modulus obtained by the measurement.

Relation between resin particles and other components

The storage elastic modulus G' is obtained by dynamic viscoelasticity measurement at a temperature rise rate of 2℃per minute, and the measurement method is as described above.

When the storage elastic modulus of the resin particles in the range of 90 ℃ to 150 ℃ is G '(p 90 to 150), the storage elastic modulus of the toner particles is G' (t 90 to 150), and the storage elastic modulus of the components after the removal of the resin particles from the toner particles is G '(r 90 to 150), G' (p 90 to 150) is preferably 1×10, for example ⁴ Pa or more and 1×10 ⁶ Pa or less, and log '(t 90-150) -log' (r 90-150) is 1.0 or more and 4.0 or less.

The value of log '(t 90-150) -log' (r 90-150) is, for example, more preferably 1.0 or more and 3.5 or less, still more preferably 1.1 or more and 3.4 or less, and particularly preferably 1.2 or more and 3.3 or less.

The values of log G '(t 90-150) -log G' (r 90-150) represent differences in viscoelasticity between toner particles when resin particles are added and when resin particles are not added. The resin particles are dispersed in a nearly uniform state and contained in the toner particles, whereby the influence of the viscoelasticity of the resin particles on the viscoelasticity of the toner particles as a whole is suppressed, and by setting the values of log G '(t 90-150) -log G' (r 90-150) in the above-described range, good fixability is achieved and the difference in glossiness of the fixed image due to the fixing conditions is reduced as compared with the case where the values are smaller than the above-described range and the case where the values are larger than the above-described range.

[ fatty acid Metal salt particles ]

Examples of the metal constituting the fatty acid metal salt contained in the fatty acid metal salt particles include zinc, calcium, magnesium, barium, aluminum, lithium, potassium, and the like, and zinc, calcium, and magnesium are preferable.

The fatty acid constituting the fatty acid metal salt contained in the fatty acid metal salt particles may be a saturated fatty acid or an unsaturated fatty acid, and examples thereof include butyric acid, valeric acid, stearic acid, lauric acid, linoleic acid, oleic acid, palmitic acid, myristic acid, caprylic acid, caproic acid, alginic acid, arachic acid, and behenic acid.

The fatty acid metal salt contained in the fatty acid metal salt particles is preferably a metal stearate or a metal laurate from the viewpoints of functionality as a lubricant, stability of a compound, and easy availability.

Examples of the metal stearate contained in the fatty acid metal salt particles include zinc stearate, calcium stearate, magnesium stearate, barium stearate, aluminum stearate, lithium stearate, and potassium stearate.

Examples of the metal laurate contained in the fatty acid metal salt particles include zinc laurate, calcium laurate, magnesium laurate, barium laurate, aluminum laurate, lithium laurate, potassium laurate, and the like.

The fatty acid metal salt contained in the fatty acid metal salt particles is preferably zinc stearate, for example, from the viewpoints of functionality as a lubricant, stability of a compound, and easy availability. That is, zinc stearate particles are preferable as fatty acid metal salt particles, for example.

Examples of the method for producing fatty acid metal salt particles include a method in which a fatty acid alkali metal salt is substituted with a cation; a method of directly reacting a fatty acid with a metal hydroxide; etc.

Examples of the method for producing zinc stearate particles include a method in which sodium stearate is substituted with cations; a method of reacting stearic acid with zinc hydroxide; etc.

The average primary particle diameter of the fatty acid metal salt particles is not particularly limited. For example, the particle diameter of the toner particles may be set.

The average primary particle diameter of the fatty acid metal salt particles is preferably, for example, 0.5 μm or more and 15 μm or less. The average primary particle diameter of the fatty acid metal salt particles is, for example, preferably 0.5 μm or more from the viewpoint of suppressing aggregation of the fatty acid metal salt particles, and is, for example, preferably 15 μm or less from the viewpoint of not damaging the image holder cleaning blade.

The average primary particle diameter of the fatty acid metal salt particles is, for example, more preferably 5 μm to 15 μm, still more preferably 6 μm to 12 μm, particularly preferably 8 μm to 10 μm, from the viewpoint that the amount of fatty acid metal salt particles supplied to the image holder is not easily reduced when an image having a low image density (for example, an image density of 1%) is formed under a high-temperature and high-humidity environment (for example, a temperature of 28 ℃ and a relative humidity of 85%), and as a result, the image holder is excellent in cleanability, and color streaks are not easily generated in the image.

The average primary particle diameter of the fatty acid metal salt particles is, for example, more preferably 0.5 μm or more and 3 μm or less, still more preferably 0.5 μm or more and 2 μm or less, and particularly preferably 1 μm or more and 2 μm or less, from the viewpoint that the difference in the supply amount of the fatty acid metal salt particles to the image portion and the non-image portion is less likely to occur when an image having the image portion and the non-image portion is formed in a high-temperature and high-humidity environment (for example, a temperature of 28 ℃ and a relative humidity of 85%).

The average primary particle diameter of the fatty acid metal salt particles was determined by the following measurement method.

First, fatty acid metal salt particles are separated from toner. The method for separating the fatty acid metal salt particles from the toner is not limited, and for example, after applying ultrasonic waves to a dispersion liquid obtained by dispersing the toner in water containing a surfactant, the dispersion liquid is centrifuged at a high speed to separate the toner particles, fatty acid metal salt particles, silica particles and other particles by centrifugation according to specific gravity. Extracting, fractionating and drying fatty acid metal salt particles to obtain fatty acid metal salt particles.

Next, the fatty acid metal salt particles were added to an aqueous electrolyte solution (isotonic aqueous solution), and ultrasonic waves were applied for 30 seconds or longer to disperse the particles. The particle size was measured using a laser diffraction scattering particle size distribution measuring apparatus (for example, microtrac MT3000II, manufactured by microtricel corp.) using this dispersion as a sample, and the particle size obtained by accumulating the particle size from the smaller side of the volume-based particle size distribution to 50% was used as the average primary particle size.

The external addition amount of the fatty acid metal salt particles is, for example, preferably 0.005 parts by mass or more and 1 part by mass or less, more preferably 0.01 parts by mass or more and 0.5 parts by mass or less, and still more preferably 0.02 parts by mass or more and 0.3 parts by mass or less, relative to 100 parts by mass of the toner particles.

[ silica particles (A) ]

The silica particles (A) have a nitrogen-containing compound containing a molybdenum element, and the Net strength N of the molybdenum element is measured by fluorescent X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si Is 0.035 to 0.45 inclusive.

Hereinafter, the "nitrogen-containing element compound containing molybdenum element" is referred to as "molybdenum-containing nitrogen compound".

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the molybdenum element of the silica particles (a) has Net strength N _Mo For example, it is preferably 5 to 75kcps, more preferably 7 to 55kcps, still more preferably 8 to 50kcps, still more preferably 10 to 40 kcps.

Net strength N of molybdenum element in silica particles _Mo And Net strength N of silicon element _Si The measurement method of (2) is as follows.

A disc having a diameter of 50mm and a thickness of 2mm was produced by compressing silica particles by a compression molding machine for about 0.5g under a load of 6t for 60 seconds. The discs were used as samples, and qualitative and quantitative elemental analyses were performed using a scanning fluorescent X-ray analyzer (XRF-1500, manufactured by SHIMADZU CORPORATION) under the following conditions, to obtain Net intensities (unit: kilo counts per second, kcps) of molybdenum element and silicon element, respectively.

Guan Dianya: 40kV (kilovolt)

Guan Dianliu: 90mA

Area measured (analytical diameter): diameter of 10mm

Measurement time: 30 minutes

To the cathode: rhodium

The external addition amount of the silica particles (a) is, for example, preferably 0.1 to 3.0 parts by mass, more preferably 0.1 to 2.0 parts by mass, and still more preferably 0.1 to 1.0 parts by mass, based on 100 parts by mass of the toner particles.

The silica particles (A) have a molybdenum-nitrogen-containing compound. The structure of the silica particles (a) will be described below.

As an embodiment of the silica particles (a), there are exemplified silica particles having a coating structure in which at least a part of the surface of a silica master batch is coated with a reaction product of a silane coupling agent and a molybdenum-containing nitrogen compound is attached to the reaction product. In the present embodiment, a hydrophobizing structure (a structure obtained by treating silica particles with a hydrophobizing agent) may be further attached to the coating structure of the reaction product. The silane coupling agent is, for example, preferably at least one selected from the group consisting of a 1-functional silane coupling agent, a 2-functional silane coupling agent, and a 3-functional silane coupling agent, and more preferably a 3-functional silane coupling agent.

Silica masterbatch-

The silica master batch may be dry silica or wet silica.

Examples of the dry silica include fumed silica (fumed silica) obtained by burning a silane compound; deflagration method silicon dioxide obtained by explosion combustion of metal silicon powder.

Examples of the wet silica include wet silica obtained by neutralization reaction of sodium silicate and an inorganic acid (precipitated silica synthesized/aggregated under alkaline conditions, gel silica synthesized/aggregated under acidic conditions); colloidal silica obtained by polymerizing acidic silicic acid while making it basic; sol-gel silica obtained by hydrolysis of an organosilane compound (e.g., an alkoxysilane). As the silica master batch, sol-gel silica is preferable from the viewpoint of narrowing the charge distribution, for example.

Reaction products of silane coupling agents

The structure constituted by the reaction product of the silane coupling agent (in particular, the reaction product of the 3-functional silane coupling agent) has a pore structure and has high affinity with the molybdenum-nitrogen-containing compound. Therefore, the molybdenum-nitrogen-containing compound enters deep into the pores, and the content of the molybdenum-nitrogen-containing compound contained in the silica particles (a) becomes relatively large.

When the surface of the silica master batch is negatively charged, the molybdenum-nitrogen-containing compound having positive charging is attached to the surface, thereby producing an effect of canceling excessive negative charging of the silica master batch. The molybdenum-containing nitrogen compound adheres to the inside of the coating structure (i.e., pore structure) composed of the reaction product of the silane coupling agent, not the outermost surface of the silica particles (a), and therefore the charged distribution of the silica particles (a) does not spread to the positively charged side, and narrowing of the charged distribution of the silica particles (a) is achieved by counteracting excessive negative charging of the silica master batch.

The silane coupling agent is preferably a compound containing no N (nitrogen element), for example. The silane coupling agent may be represented by the following formula (TA).

Formula (TA) R ¹ _n -Si(OR ² ) _4-n

In the formula (TA), R ¹ Is of carbon sourceA saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ² Is halogen atom or alkyl, n is 1, 2 or 3. When n is 2 or 3, a plurality of R ¹ May be the same group or may be different groups. When n is 1 or 2, a plurality of R ² May be the same group or may be different groups.

The reaction product of the silane coupling agent may be, for example, OR in the formula (TA) ² A reaction product in which all or part of (a) is substituted with OH groups; OR (OR) ² A reaction product obtained by polycondensation of all or a part of the groups substituted with OH groups with each other; OR (OR) ² And a reaction product obtained by polycondensation of all or a part of the groups substituted with OH groups with SiOH groups of the silica master batch.

R in formula (TA) ¹ The aliphatic hydrocarbon group may be any of linear, branched, and cyclic, and for example, linear or branched is preferable. The aliphatic hydrocarbon group has, for example, preferably 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms, still more preferably 1 to 12 carbon atoms, and still more preferably 1 to 10 carbon atoms. The aliphatic hydrocarbon group may be either saturated or unsaturated, but is preferably a saturated aliphatic hydrocarbon group, and more preferably an alkyl group, for example. The hydrogen atom of the aliphatic hydrocarbon group may be substituted with a halogen atom.

Examples of the saturated aliphatic hydrocarbon group include a linear alkyl group (methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, hexadecyl, eicosyl, etc.), a branched alkyl group (isopropyl, isobutyl, isopentyl, neopentyl, 2-ethylhexyl, tert-butyl, tert-amyl, isopentyl, etc.), a cyclic alkyl group (cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, tricyclodecyl, norbornyl, adamantyl, etc.), and the like.

Examples of the unsaturated aliphatic hydrocarbon group include an alkenyl group (vinyl group, 1-propenyl group, 2-butenyl group, 1-hexenyl group, 2-dodecenyl group, pentenyl group and the like), an alkynyl group (ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 3-hexynyl group, 2-dodecenyl group and the like), and the like.

R in formula (TA) ¹ The aromatic hydrocarbon group represented is preferably a carbon number of 6 to 20, more preferably a carbon number of 6 to 18, still more preferably a carbon number of 6 to 12, and still more preferably a carbon number of 6 to 10. Examples of the aromatic hydrocarbon group include phenylene, biphenylene, terphenylene (terphenyl), naphthyl, and anthracenyl. The hydrogen atom of the aromatic hydrocarbon group may be substituted with a halogen atom.

As R in the formula (TA) ² Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom, a bromine atom, and an iodine atom are preferable.

As R in the formula (TA) ² The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and still more preferably an alkyl group having 1 to 4 carbon atoms. Examples of the straight-chain alkyl group having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl. Examples of the branched alkyl group having 3 to 10 carbon atoms include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isoheptyl, sec-heptyl, tert-heptyl, isooctyl, sec-octyl, tert-octyl, isononyl, sec-nonyl, tert-nonyl, isodecyl, zhong Guiji, tert-decyl and the like. Examples of the cyclic alkyl group having 3 to 10 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl and a polycyclic (for example, bicyclic, tricyclic, spirocyclic) alkyl group obtained by connecting these monocyclic alkyl groups. The hydrogen atom of the alkyl group may be substituted with a halogen atom.

N in the formula (TA) is 1, 2 or 3, for example, preferably 1 or 2, more preferably 1.

The silane coupling agent represented by the formula (TA) is preferably R ¹ A saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms, R ² Is halogenAn atom or an alkyl group having 1 to 10 carbon atoms and n is 1.

Examples of the 3-functional silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, n-octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, hexyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, phenyltrimethoxysilane, o-methylphenyl trimethoxysilane, p-methylphenyl trimethoxysilane, phenyltriethoxysilane, benzyltriethoxysilane, decyltrichlorosilane, and phenyltrichlorosilane (R in formula (TA) above) ¹ A compound which is an unsubstituted aliphatic hydrocarbon group or an unsubstituted aromatic hydrocarbon group; 3-glycidoxypropyl trimethoxysilane, gamma-methacryloxypropyl trimethoxysilane, gamma-mercaptopropyl trimethoxysilane, gamma-chloropropyl trimethoxysilane, gamma-glycidoxypropyl methyldimethoxy silane (R in formula (TA) above ¹ A compound which is a substituted aliphatic hydrocarbon group or a substituted aromatic hydrocarbon group); etc. The 3-functional silane coupling agent may be used singly or in combination of two or more.

As 3-functional silane coupling agents, for example, preference is given to alkyltrialkoxysilanes, more preferably R in the formula (TA) ¹ An alkyl group having 1 to 20 carbon atoms (for example, preferably 1 to 15 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 4 carbon atoms, particularly preferably 1 or 2 carbon atoms) and R ² An alkyl trialkoxysilane which is an alkyl group having 1 to 2 carbon atoms.

More specifically, for example, at least one 3-functional silane coupling agent selected from the group consisting of alkyl trimethoxysilane and alkyl triethoxysilane having 1 to 20 carbon atoms inclusive, is preferable as the silane coupling agent constituting the coating structure of the silica master batch surface;

more preferably at least one 3-functional silane coupling agent selected from the group consisting of alkyl trimethoxysilane and alkyl triethoxysilane having 1 to 15 carbon atoms in the alkyl group;

further preferably at least one 3-functional silane coupling agent selected from the group consisting of alkyl trimethoxysilane and alkyl triethoxysilane having 1 to 8 carbon atoms in the alkyl group;

Further preferably at least one 3-functional silane coupling agent selected from the group consisting of alkyl trimethoxysilane and alkyl triethoxysilane having 1 to 4 carbon atoms inclusive of alkyl groups;

particularly preferred is at least one 3-functional silane coupling agent selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane and ethyltriethoxysilane.

The coating structure composed of the reaction product of the silane coupling agent is preferably 5.5 mass% or more and 30 mass% or less, more preferably 7 mass% or more and 22 mass% or less, with respect to the entire silica particle (a), for example.

Molybdenum-containing nitrogen compounds

The molybdenum-containing nitrogen compound is a nitrogen element-containing compound containing molybdenum element other than ammonia and a compound that is gaseous at a temperature of 25 ℃ or lower.

The molybdenum-nitrogen-containing compound is preferably attached to the inside of a coating structure (i.e., the inside of a pore structure) composed of a reaction product of a silane coupling agent, for example. The molybdenum-nitrogen-containing compound may be one kind or two or more kinds.

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the molybdenum-containing nitrogen compound is preferably at least one selected from the group consisting of a quaternary ammonium salt containing a molybdenum element (in particular, a quaternary ammonium molybdate salt) and a mixture of a quaternary ammonium salt and a metal oxide containing a molybdenum element. In the quaternary ammonium salt containing molybdenum element, the bond between the anion containing molybdenum element and the quaternary ammonium cation is strong, so that the charge distribution maintenance property is high, and the effect of appropriately suppressing polarization derived from nitrogen atoms in the silica particles (a) can be stably obtained.

As the molybdenum-nitrogen-containing compound, for example, a compound represented by the following formula (1) is preferable.

[ chemical formula 1]

(1)

In the formula (1), R ¹ 、R ² 、R ³ R is R ⁴ Each independently represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and X-represents an anion containing molybdenum element. Wherein R is ¹ 、R ² 、R ³ R is R ⁴ At least one of which represents an alkyl group, an aralkyl group or an aryl group. R is R ¹ 、R ² 、R ³ R is R ⁴ May be linked to form an aliphatic ring, an aromatic ring or a heterocyclic ring. Here, the alkyl group, the aralkyl group, and the aryl group may have a substituent.

As represented by R ¹ ～R ⁴ Examples of the alkyl group include a linear alkyl group having 1 to 20 carbon atoms and a branched alkyl group having 3 to 20 carbon atoms. Examples of the linear alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, and n-hexadecyl. Examples of the branched alkyl group having 3 to 20 carbon atoms include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isoheptyl, sec-heptyl, tert-heptyl, isooctyl, sec-octyl, tert-octyl, isononyl, sec-nonyl, tert-nonyl, isodecyl, zhong Guiji, tert-decyl and the like.

As represented by R ¹ ～R ⁴ The alkyl group is preferably an alkyl group having 1 to 15 carbon atoms such as methyl, ethyl, butyl, and tetradecyl.

As represented by R ¹ ～R ⁴ The aralkyl group represented by the formula (I) may be a C7 or more and 30 or moreLower aralkyl. Examples of the aralkyl group having 7 to 30 carbon atoms include benzyl, phenylethyl, phenylpropyl, 4-phenylbutyl, phenylpentyl, phenylhexyl, phenylheptyl, phenyloctyl, phenylnonyl, naphthylmethyl, naphthylethyl, anthrylmethyl, phenyl-cyclopentylmethyl and the like.

As represented by R ¹ ～R ⁴ The aralkyl group is preferably an aralkyl group having 7 to 15 carbon atoms such as benzyl, phenylethyl, phenylpropyl, and 4-phenylbutyl.

As represented by R ¹ ～R ⁴ Examples of the aryl group include aryl groups having 6 to 20 carbon atoms. Examples of the aryl group having 6 to 20 carbon atoms include phenyl, pyridyl, and naphthyl.

As represented by R ¹ ～R ⁴ The aryl group represented is preferably an aryl group having 6 to 10 carbon atoms such as a phenyl group.

As R ¹ 、R ² 、R ³ R is R ⁴ Examples of the ring formed by connecting two or more of these compounds to each other include alicyclic rings having 2 or more and 20 or less carbon atoms, heterocyclic amines having 2 or more and 20 or less carbon atoms, and the like.

R ¹ 、R ² 、R ³ R is R ⁴ Each of which may independently have a substituent. Examples of the substituent include a nitrile group, a carbonyl group, an ether group, an amide group, a siloxane group, a silyl group, and an alkoxysilane group.

R ¹ 、R ² 、R ³ R is R ⁴ For example, it is preferable that the alkyl group having 1 to 16 carbon atoms, the aralkyl group having 7 to 10 carbon atoms, or the aryl group having 6 to 20 carbon atoms are independently represented.

From X ^- The molybdenum-containing anion is preferably a molybdate ion, more preferably a molybdate ion having a valence of 4 or 6, and still more preferably a molybdate ion having a valence of 6. As the molybdate ion, moO is preferable, for example ₄ ^2- 、Mo ₂ O ₇ ^2- 、Mo ₃ O ₁₀ ^2- 、Mo ₄ O ₁₃ ^2- 、Mo ₇ O ₂₄ ^2- 、Mo ₈ O ₂₆ ^4- 。

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the compound represented by the formula (1) preferably has a total carbon number of 18 to 35, more preferably 20 to 32.

The following examples show compounds represented by formula (1). The present embodiment is not limited thereto.

[ chemical formula 2]

As the molybdenum element-containing quaternary ammonium salt, [ N ] ⁺ (CH) ₃ (C ₁₄ C ₂₉ ) ₂ ] ₄ Mo ₈ O ₂₈ ^4- 、[N ⁺ (C ₄ H ₉ ) ₂ (C ₆ H ₆ ) ₂ ] ₂ Mo ₂ O ₇ ^2- 、[N ⁺ (CH ₃ ) ₂ (CH ₂ C ₆ H ₆ )(CH ₂ ) ₁₇ CH ₃ ] ₂ MoO ₄ ^2- 、[N ⁺ (CH ₃ ) ₂ (CH ₂ C ₆ H ₆ )(CH ₂ ) ₁₅ CH ₃ ] ₂ MoO ₄ ^2- And quaternary ammonium isosolybdate.

Examples of the metal oxide containing molybdenum element include molybdenum oxide (molybdenum trioxide, molybdenum dioxide, mo ₉ O ₂₆ ) Alkali metal molybdate (lithium molybdate, sodium molybdate, potassium molybdate, etc.), molybdenum alkaline earth metal salt (magnesium molybdate, calcium molybdate, etc.), other composite oxide (Bi) ₂ O ₃ ·2MoO ₃ 、γ-Ce ₂ Mo ₃ O ₁₃ Etc.).

The silica particles (A) detect molybdenum-containing nitrogen compounds when heated in a temperature range of 300 ℃ to 600 ℃. The molybdenum-nitrogen-containing compound can be produced by a method comprising the steps of passing an inert gas at 300 ℃ or higher and 600 ℃ or lowerFor example, using a furnace-type falling-down thermal decomposition gas chromatograph mass spectrometer using He as a carrier gas. Specifically, 0.1mg to 10mg of silica particles were introduced into a pyrolysis gas chromatograph mass spectrometer, and whether or not a molybdenum-nitrogen compound was contained was confirmed from the MS spectrum of the detected peak. Examples of the component produced by thermal decomposition from the silica particles containing the molybdenum-nitrogen compound include a primary amine, a secondary amine, or a tertiary amine represented by the following formula (2), or an aromatic nitrogen compound. R of formula (2) ¹ 、R ² R is R ³ Respectively with R of formula (1) ¹ 、R ² R is R ³ Meaning the same. In the case where the molybdenum-nitrogen-containing compound is a quaternary ammonium salt, a part of the side chain is detached by thermal decomposition at 600 ℃.

[ chemical formula 3]

(2)

Molybdenum-free nitrogen-containing compound

In the silica particles (a), a nitrogen element-containing compound containing no molybdenum element may be attached to the pores of the reaction product of the silane coupling agent. The nitrogen-containing element compound containing no molybdenum element includes, for example, at least one selected from the group consisting of a quaternary ammonium salt, a primary amine compound, a secondary amine compound, a tertiary amine compound, an amide compound, an imine compound, and a nitrile compound. The nitrogen-containing element compound not containing molybdenum element is preferably, for example, a quaternary ammonium salt.

Specific examples of the primary amine compound include phenethylamine, toluidine, catecholamine, and 2,4, 6-trimethylaniline.

Specific examples of the secondary amine compound include dibenzylamine, 2-nitrodiphenylamine, and 4- (2-octylamino) diphenylamine.

Specific examples of the tertiary amine compound include 1, 8-bis (dimethylamino) naphthalene, N-dibenzyl-2-aminoethanol, and N-benzyl-N-methylethanolamine.

Specific examples of the amide compound include N-cyclohexyl-p-toluenesulfonamide, 4-acetamide-1-benzylpiperidine, and N-hydroxy-3- [1- (phenylsulfanyl) methyl-1H-1, 2, 3-triazol-4-yl ] benzamide.

Specific examples of the imine compound include benzophenone imine, 2, 3-bis (2, 6-diisopropylphenylimino) butane, and N, N' - (ethane-1, 2-diyl) bis (2, 4, 6-trimethylaniline).

Specific examples of the nitrile compound include 3-indoleacetonitrile, 4- [ (4-chloro-2-pyrimidinyl) amino ] benzonitrile, and 4-bromo-2, 2-diphenylbutyronitrile.

The quaternary ammonium salt may be a compound represented by the following formula (AM). The compound represented by the formula (AM) may be one kind or two or more kinds.

[ chemical formula 4]

(AM)

In the formula (AM), R ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ Each independently represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and Z-represents an anion. Wherein R is ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ At least one of which is alkyl, aralkyl or aryl. R is R ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ May be linked to form an aliphatic ring, an aromatic ring or a heterocyclic ring. Here, the alkyl group, the aralkyl group, and the aryl group may have a substituent.

As represented by R ¹¹ ～R ¹⁴ Examples of the alkyl group include a linear alkyl group having 1 to 20 carbon atoms and a branched alkyl group having 3 to 20 carbon atoms. Examples of the linear alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, and n-hexadecyl. Examples of the branched alkyl group having 3 to 20 carbon atoms include isopropyl, isobutyl and sec-butylA group, a tertiary butyl group, an isopentyl group, a neopentyl group, a tertiary pentyl group, an isohexyl group, a secondary hexyl group, a tertiary hexyl group, an isoheptyl group, a secondary heptyl group, a tertiary heptyl group, an isooctyl group, a secondary octyl group, a tertiary octyl group, an isononyl group, a secondary nonyl group, a tertiary nonyl group, an isodecyl group, a Zhong Guiji group, a tertiary decyl group, and the like.

As represented by R ¹¹ ～R ¹⁴ The alkyl group is preferably an alkyl group having 1 to 15 carbon atoms such as methyl, ethyl, butyl, and tetradecyl.

As represented by R ¹¹ ～R ¹⁴ The aralkyl group represented by the above-mentioned formula may be an aralkyl group having 7 to 30 carbon atoms. Examples of the aralkyl group having 7 to 30 carbon atoms include benzyl, phenylethyl, phenylpropyl, 4-phenylbutyl, phenylpentyl, phenylhexyl, phenylheptyl, phenyloctyl, phenylnonyl, naphthylmethyl, naphthylethyl, anthrylmethyl, phenyl-cyclopentylmethyl and the like.

As represented by R ¹¹ ～R ¹⁴ The aralkyl group is preferably an aralkyl group having 7 to 15 carbon atoms such as benzyl, phenylethyl, phenylpropyl, and 4-phenylbutyl.

As represented by R ¹¹ ～R ¹⁴ Examples of the aryl group include aryl groups having 6 to 20 carbon atoms. Examples of the aryl group having 6 to 20 carbon atoms include phenyl, pyridyl, and naphthyl.

As represented by R ¹¹ ～R ¹⁴ The aryl group represented is preferably an aryl group having 6 to 10 carbon atoms such as a phenyl group.

As R ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ Examples of the ring formed by connecting two or more of these compounds to each other include alicyclic rings having 2 or more and 20 or less carbon atoms, heterocyclic amines having 2 or more and 20 or less carbon atoms, and the like.

R ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ Each of which may independently have a substituent. Examples of the substituent include a nitrile group, a carbonyl group, an ether group, an amide group, a siloxane group, a silyl group, and an alkoxysilane group.

R ¹¹ 、R ¹² 、R ¹³ R is R ¹⁴ For example, it is preferable that the alkyl group having 1 to 16 carbon atoms, the aralkyl group having 7 to 10 carbon atoms, or the aryl group having 6 to 20 carbon atoms are independently represented.

From Z ^- The anions represented may be any of organic anions and inorganic anions.

Examples of the organic anions include polyfluoroalkyl sulfonate ion, polyfluoroalkyl carboxylate ion, tetraphenyl borate ion, aromatic carboxylate ion, and aromatic sulfonate ion (1-naphthol-4-sulfonate ion, etc.).

As inorganic anions, mention may be made of OH ^- 、F ^- 、Fe(CN) ₆ ^3- 、Cl ^- 、Br ^- 、NO ₂ ^- 、NO ₃ ^- 、CO ₃ ^2- 、PO ₄ ^3- 、SO ₄ ^2- Etc.

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the compound represented by the formula (AM) preferably has a total carbon number of 18 to 35, more preferably 20 to 32.

The following examples show compounds represented by formula (AM). The present embodiment is not limited thereto.

[ chemical formula 5]

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the total content of the molybdenum-containing nitrogen compound and the nitrogen-containing element compound containing no molybdenum element contained in the silica particles (a) is, for example, preferably 0.005 or more and 0.50 or less, more preferably 0.008 or more and 0.45 or less, still more preferably 0.015 or more and 0.20 or less, and still more preferably 0.018 or more and 0.10 or less in terms of the mass ratio N/Si of nitrogen element to silicon element.

The mass ratio N/Si of the silica particles (A) was determined as the mass ratio of N atoms to Si atoms (N/Si) by measuring the mass ratio with an oxygen/nitrogen analyzer (for example, HORIBA, ltd. EMGA-920) for 45 seconds. The sample was subjected to vacuum drying at 100℃for 24 hours or more as a pretreatment to remove impurities such as ammonia.

The total extraction amount X of the molybdenum-containing nitrogen compound and the nitrogen-containing element compound not containing molybdenum element extracted from the silica particles (a) by the ammonia/methanol mixed solution is preferably, for example, 0.1 mass% or more relative to the mass of the silica particles (a). The total extraction amount X of the molybdenum-containing nitrogen compound and the nitrogen-containing element compound not containing molybdenum element extracted from the silica particles (a) by the ammonia/methanol mixed solution and the total extraction amount Y of the molybdenum-containing nitrogen compound and the nitrogen-containing element compound not containing molybdenum element extracted from the silica particles (a) by water (the mass ratio to the mass of the silica particles (a) is preferably Y/X < 0.3, for example.

The above relationship indicates that the nitrogen element-containing compound contained in the silica particles (a) has a property of being hardly dissolved in water (i.e., a property of being hardly adsorbed with water in the air). Therefore, the above relationship results in narrowing of the charge distribution of the silica particles (a) and excellent charge distribution maintenance.

The extraction amount X is preferably, for example, 0.25 mass% or more and 6.5 mass% or less relative to the mass of the silica particles (a). The ratio Y/X of the extraction amount X to the extraction amount Y is desirably 0.

The extraction amount X and the extraction amount Y were measured by the following methods.

The silica particles were analyzed at 400℃by a thermogravimetric/mass spectrometry analyzer (for example, NETZSCH Japan K.K., gas chromatograph mass spectrometer), and the mass fraction of the compound in which a hydrocarbon having 1 or more carbon atoms was covalently bonded to a nitrogen atom was measured with respect to the silica particles, and was integrated, and this was designated as W1.

To 30 parts by mass of an ammonia/methanol solution (ammonia/methanol mass ratio=1/5.2, manufactured by Sigma-Aldrich) having a liquid temperature of 25 ℃, 1 part by mass of silica particles was added, and after 30 minutes of ultrasonic treatment, the silica powder and the extract were separated. The separated silica particles were dried at 100℃for 24 hours by a vacuum dryer, and the mass fraction of the compound having a hydrocarbon having 1 or more carbon atoms covalently bonded to a nitrogen atom was measured at 400℃by a thermogravimetric/mass spectrometry analysis device, relative to the silica particles, and was calculated as W2.

1 part by mass of silica particles was added to 30 parts by mass of water at a liquid temperature of 25℃and subjected to ultrasonic treatment for 30 minutes, followed by separation of the silica particles and the extract. The separated silica particles were dried at 100℃for 24 hours by a vacuum dryer, and the mass fraction of the compound having a hydrocarbon having 1 or more carbon atoms covalently bonded to a nitrogen atom was measured at 400℃by a thermogravimetric/mass spectrometry analysis device, relative to the silica particles, and was calculated as W3.

The extraction amount x=w1-W2 is calculated from W1 and W2.

The extraction amount y=w1-W3 is calculated from W1 and W3.

Hydrophobization of structures

In the silica particles (a), a hydrophobizing structure (a structure obtained by treating silica particles with a hydrophobizing agent) may be attached to a coating structure of a reaction product of the silane coupling agent.

As the hydrophobizing agent, for example, an organosilicon compound is suitable. Examples of the organosilicon compound include the following compounds.

Alkoxy silane compounds or halogenated silane compounds having a lower alkyl group such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylchlorosilane, and trimethylmethoxysilane.

Vinyl alkoxysilane compounds such as vinyltrimethoxysilane and vinyltriethoxysilane.

Alkoxysilane compounds having an epoxy group such as 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, and 3-glycidoxypropyl triethoxysilane.

Alkoxysilane compounds having a styryl group such as p-styryltrimethoxysilane and p-styryltriethoxysilane.

Aminoalkyl-containing alkoxysilane compounds such as N-2- (aminoethyl) -3-aminopropyl methyldimethoxy silane, N-2- (aminoethyl) -3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane, 3-triethoxysilyl-N- (1, 3-dimethyl-butylene) propylamine, and N-phenyl-3-aminopropyl trimethoxy silane.

Alkoxysilane compounds having an isocyanate alkyl group such as 3-isocyanatopropyl trimethoxysilane and 3-isocyanatopropyl triethoxysilane.

Silane compounds such as hexamethyldisilazane and tetramethyldisilazane.

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution and attracting the fatty acid metal salt particles and electrostatically fixing them to the toner particle surfaces, the silica particles (a) preferably have the following characteristics, for example.

Average roundness, average primary particle diameter, number particle size distribution index-

The average roundness of the silica particles (a) is, for example, preferably 0.60 to 0.96, more preferably 0.65 to 0.94, still more preferably 0.70 to 0.92, and still more preferably 0.75 to 0.90.

The silica particles (a) are preferably, for example, monodisperse particles having one peak in a region having a roundness of more than 0.88 in the roundness distribution of the primary particles.

The average primary particle diameter of the silica particles (A) is, for example, preferably 10nm to 120nm, more preferably 20nm to 100nm, still more preferably 30nm to 90nm, particularly preferably 40nm to 80 nm.

The number particle size distribution index of the silica particles (a) is, for example, preferably 1.1 to 2.0, more preferably 1.15 to 1.6.

The average roundness, average primary particle diameter, and number particle size distribution index of the silica particles (a) were measured as follows.

Using energy dispersive X-ray analysis mountedDevice (EDX device) (HORIBA, ltd. EMAX evaluation X-Max80 mm) ² ) Scanning Electron Microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, S-4800) photographs toner at a magnification of 4 ten thousand times. 200 silica particles (A) were determined from one field of view by EDX analysis based on the presence of Mo element, N element and Si element. 200 silica particle (A) images were analyzed using image processing analysis software WinRoof (MITANI CORPORATION). The circle equivalent diameter, area and circumference of each primary particle image were obtained, and the roundness=4pi× (area of particle image)/(circumference of particle image) was obtained ² . In the distribution of roundness, the roundness at the time of accumulating to 50% from the smaller side is taken as the average roundness. In the distribution of the equivalent circle diameters, the equivalent circle diameter at the time of 50% of the cumulative small diameter side is taken as the average primary particle diameter. In the distribution of the equivalent circle diameters, the particle diameter when the number of particles is 16% from the small diameter side was D16, the particle diameter when the number of particles is 84% was D84, and the number particle size distribution index= (D84/D16) was obtained ^0.5 。

Degree of hydrophobization-

The degree of hydrophobization of the silica particles (a) is, for example, preferably 10% or more and 60% or less, more preferably 20% or more and 55% or less, and still more preferably 28% or more and 53% or less.

The method for measuring the degree of hydrophobicity of the silica particles is as follows.

To 50ml of deionized water, 0.2 mass% of silica particles was added, and methanol was added dropwise from a burette while stirring with a magnetic stirrer, and the mass fraction of methanol in the methanol-water mixed solution at the end of the precipitation of the total amount of the sample was determined as the degree of hydrophobization.

Volume resistivity-

The volume resistivity R of the silica particles (A) is, for example, preferably 1.0X10 ⁷ Omega cm or more and 1.0X10 ^12.5 Omega cm or less, more preferably 1.0X10 ^7.5 Omega cm or more and 1.0X10 ¹² Omega cm or less, more preferably 1.0X10 ⁸ Omega cm or more and 1.0X10 ^11.5 Omega cm or less, more preferably 1.0X10 ⁹ Omega cm or more and 1.0X10 ¹¹ Omega cm or less. Silica particles(A) The volume resistivity R of (c) may be adjusted according to the content of the molybdenum-nitrogen-containing compound.

In the silica particles (a), when Ra and Rb are the volume resistivity before and after calcination at 350 ℃, the ratio Ra/Rb is preferably, for example, 0.01 to 0.8, more preferably 0.015 to 0.6.

The volume resistivity Ra (meaning the same as the volume resistivity R) of the silica particles (A) before calcination at 350℃is preferably 1.0X10, for example ⁷ Omega cm or more and 1.0X10 ^12.5 Omega cm or less, more preferably 1.0X10 ^7.5 Omega cm or more and 1.0X10 ¹² Omega cm or less, more preferably 1.0X10 ⁸ Omega cm or more and 1.0X10 ^11.5 Omega cm or less, more preferably 1.0X10 ⁹ Omega cm or more and 1.0X10 ¹¹ Omega cm or less.

Calcination at 350 ℃ was warmed to 350 ℃ at a warming rate of 10 ℃/min under nitrogen atmosphere, held at 350 ℃ for 3 hours, and cooled to room temperature (25 ℃) at a cooling rate of 10 ℃/min.

The volume resistivity of the silica particles (A) was measured at a temperature of 20℃and a relative humidity of 50% as follows.

Is configured with 20cm ² Silica particles (A) having a thickness of about 1mm or more and 3mm or less are placed on the surface of the circular jig of the electrode plate to form a silica particle layer. 20cm of the silica particle layer was placed thereon ² The silica particle layer is sandwiched, and a pressure of 0.4MPa is applied to the electrode plate in order to eliminate the gaps between the silica particles. The thickness L (cm) of the silica particle layer was measured. A frequency of 10 was obtained by an impedance analyzer (manufactured by Solartron Analytical Co.) connected to both electrodes above and below the silica particle layer ^-3 Hz above and 10 ⁶ Nyquist plot for the range below Hz. The volume resistance R (Ω) is obtained by fitting three resistance components, i.e., the volume resistance, the particle interface resistance, and the electrode contact resistance, to an equivalent circuit. The volume resistivity ρ (Ω·cm) of the silica particles is calculated from the volume resistance R (Ω) and the thickness L (cm) of the silica particle layer by the formula ρ=r/L.

OH group content-

The OH group content of the silica particles (A) is, for example, preferably 0.05 pieces/nm ² Above and 6/nm ² Hereinafter, more preferably 0.1/nm ² Above and 5.5/nm ² Hereinafter, more preferably 0.15/nm ² Above and 5/nm ² Hereinafter, more preferably 0.2/nm ² Above and 4/nm ² Hereinafter, it is more preferably 0.2/nm ² Above and 3/nm ² The following is given.

The OH group content of the silica particles was measured by the Seles method as follows.

1.5g of silica particles was added to a 50g of water/50 g of ethanol mixed solution, and the mixture was stirred with an ultrasonic homogenizer for 2 minutes to prepare a dispersion. 1.0g of a 0.1mol/L aqueous hydrochloric acid solution was added dropwise while stirring at 25℃to obtain a test solution. The test solution was placed in an automatic titration apparatus, and potentiometric titration was performed using a sodium hydroxide aqueous solution of 0.01mol/L to prepare a differential curve of the titration curve. The titration amount at which the titration amount of the 0.01mol/L sodium hydroxide aqueous solution is the largest among inflection points where the differential value of the titration curve is 1.8 or more was set as E.

The surface silanol group density ρ (individual/nm) of the silica particles was calculated according to the following formula ² ) And is used as the OH group amount of the silica particles.

The formula: ρ= ((0.01×e-0.1) ×na/1000)/(mxs) _BET ×10 ¹⁸ )

E: the differential value of the titration curve is the titration amount with the largest titration amount of 0.01mol/L sodium hydroxide aqueous solution in the inflection point with more than 1.8, NA: a Fu Jiade roconstant, M: silica particle amount (1.5 g), S _BET : BET specific surface area (m) of silica particles measured by the three-point nitrogen adsorption method ² /g) (equilibrium relative pressure set to 0.3).

Pore size-

The silica particles (a) preferably have a first peak in the pore distribution curve of the nitrogen adsorption method in the range of, for example, 0.01nm to 2nm, and a second peak in the range of 1.5nm to 50nm, more preferably 2nm to 50nm, still more preferably 2nm to 40nm, and still more preferably 2nm to 30 nm.

By the first peak and the second peak being within the above ranges, the molybdenum-nitrogen-containing compound enters into the deep pores of the coating structure, and the charge distribution is narrowed.

The pore distribution curve of the nitrogen adsorption method was obtained as follows.

The silica particles were cooled to a liquid nitrogen temperature (-196 ℃) and nitrogen gas was introduced, and the adsorption amount of nitrogen gas was determined by a constant volume method or a gravimetric method. The pressure of the introduced nitrogen gas was gradually increased, and adsorption isotherms were prepared by plotting the adsorption amounts of nitrogen gas with respect to the respective equilibrium pressures. By the calculation formula of the BJH method, a pore size distribution curve whose vertical axis is frequency and whose horizontal axis is pore size is obtained from the adsorption isotherm. The cumulative pore volume distribution represented by the pore diameter was obtained from the obtained pore diameter distribution curve, and the vertical axis represents the volume, and the horizontal axis represents the position of the peak of the pore diameter was confirmed.

From the viewpoints of narrowing the charge distribution and maintaining the charge distribution, the silica particles (a) preferably satisfy any one of the following modes (a) and (B), for example.

Mode (a): when pore volumes of 1nm to 50nm, which are obtained from a pore distribution curve of a nitrogen adsorption method before and after calcination at 350 ℃, are A and B, respectively, the ratio B/A is 1.2 to 5, and B is 0.2cm ³ Above/g and 3cm ³ And/g in the following manner.

Hereinafter, "pore volume A having a pore diameter of 1nm to 50nm obtained from a pore distribution curve of a nitrogen adsorption method before calcination at 350 ℃ is referred to as" pore volume A before calcination at 350 ℃, and "pore volume B having a pore diameter of 1nm to 50nm obtained from a pore distribution curve of a nitrogen adsorption method after calcination at 350 ℃ is referred to as" pore volume B after calcination at 350) ".

The pore volume was measured as follows.

The silica particles were cooled to a liquid nitrogen temperature (-196 ℃) and nitrogen gas was introduced, and the adsorption amount of nitrogen gas was determined by a constant volume method or a gravimetric method. The pressure of the introduced nitrogen gas was gradually increased, and adsorption isotherms were prepared by plotting the adsorption amounts of nitrogen gas with respect to the respective equilibrium pressures. By the calculation formula of the BJH method, a pore size distribution curve whose vertical axis is frequency and whose horizontal axis is pore size is obtained from the adsorption isotherm. From the obtained pore size distribution curve, the cumulative pore volume distribution with the vertical axis being the volume and the horizontal axis being the pore size is obtained. Based on the obtained cumulative pore volume distribution, pore volumes having pore diameters in the range of 1nm to 50nm are cumulative, and the cumulative pore volume distribution is defined as "pore volume having pore diameters of 1nm to 50 nm.

The ratio B/a of the pore volume a before calcination at 350 ℃ to the pore volume B after calcination at 350 ℃ is, for example, preferably 1.2 to 5, more preferably 1.4 to 3, still more preferably 1.4 to 2.5.

The pore volume B after calcination at 350℃is, for example, preferably 0.2cm ³ Above/g and 3cm ³ Preferably less than or equal to/g, more preferably 0.3cm ³ Above/g and 1.8cm ³ Preferably less than or equal to/g, more preferably 0.6cm ³ Above/g and 1.5cm ³ And/g or less.

The mode (a) is a mode in which a sufficient amount of the nitrogen-containing element compound is adsorbed to at least a part of the pores of the silica particles.

Mode (B): in a method based on cross polarization/magic angle spinning (CP/MAS) ²⁹ The ratio C/D of the integrated value C of the signal observed in the range of-50 ppm or more and-75 ppm or less in the Si solid-state Nuclear Magnetic Resonance (NMR) spectrum (hereinafter referred to as "Si-CP/MAS NMR spectrum") to the integrated value D of the signal observed in the range of-90 ppm or more and-120 ppm or less is 0.10 or more and 0.75 or less.

Si-CP/MAS NMR spectrum was obtained by performing nuclear magnetic resonance spectroscopy under the following conditions.

Beam splitter: AVANCE300 (Bruker company)

Resonance frequency: 59.6MHz

Measurement core: ²⁹ Si

assay: CPMAS method (using standard parc sequence cp.av from Bruker Co.)

Latency: 4 seconds

Contact time: 8 ms of

Cumulative number of times: 2048 times

Measurement temperature: room temperature (actual measurement 25 ℃ C.)

Observation center frequency: 3975.72Hz

MAS rotation speed: 7.0mm-6kHz

Reference substance: hexamethylcyclotrisiloxane

The ratio C/D is, for example, preferably 0.10 to 0.75, more preferably 0.12 to 0.45, still more preferably 0.15 to 0.40.

When the integrated value of all signals of the si—cp/MAS NMR spectrum is set to 100%, the ratio (Signal ratio) of the integrated value C of the Signal observed in the range of the chemical shift of-50 ppm or more and-75 ppm or less is preferably 5% or more, more preferably 7% or more, for example. The upper limit of the proportion of the integrated value C of the signal is, for example, 60% or less.

The mode (B) is a mode in which at least a part of the surface of the silica particles has a low-density coating structure capable of adsorbing a sufficient amount of the nitrogen-containing element compound. The low-density coating structure is, for example, a coating structure composed of the reaction product of a silane coupling agent (in particular, a 3-functional silane coupling agent), for example, siO _2/3 CH ₃ A layer.

[ method for producing silica particles (A) ]

An example of the method for producing silica particles (a) includes: a first step of forming a coating structure composed of a reaction product of a silane coupling agent on at least a part of the surface of a silica master batch; and a second step of attaching a molybdenum-containing nitrogen compound to the coating structure. The present production method may further include a third step of subjecting the silica master batch having the coating structure to a hydrophobization treatment after or during the second step. The above steps are described in detail below.

Silica masterbatch-

The silica master batch is prepared, for example, by the following step (i) or step (ii).

Step (i) a step of preparing a silica master batch suspension by mixing an alcohol-containing solvent with the silica master batch.

Step (ii) a step of granulating the silica master batch by a sol-gel method to obtain a silica master batch suspension.

The silica master batch used in the step (i) may be dry silica or wet silica. Specifically, sol gel silica, hydrocolloid silica, alcoholic silica, fumed silica, fused silica, and the like can be mentioned.

The alcohol-containing solvent used in the step (i) may be a single alcohol solvent or a mixed solvent of an alcohol and another solvent. Examples of the alcohol include lower alcohols such as methanol, ethanol, n-propanol, isopropanol, and butanol. Examples of the other solvent include water; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and cellosolve acetate; ethers such as dioxane and tetrahydrofuran; etc. In the case of the mixed solvent, the proportion of the alcohol is, for example, preferably 80% by mass or more, and more preferably 85% by mass or more.

The step (ii) is preferably, for example, a sol-gel method including the steps of: a base catalyst solution preparation step of preparing a base catalyst solution containing a base catalyst in a solvent containing an alcohol; and a silica masterbatch production step of producing silica masterbatch by supplying tetraalkoxysilane and a base catalyst to the base catalyst solution.

The alkali catalyst solution preparation step is preferably, for example, a step of preparing a solvent containing an alcohol and mixing the solvent with an alkali catalyst to obtain an alkali catalyst solution.

The solvent containing the alcohol may be a single solvent of the alcohol or may be a mixed solvent of the alcohol and other solvents. Examples of the alcohol include lower alcohols such as methanol, ethanol, n-propanol, isopropanol, and butanol. Examples of the other solvent include water; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and cellosolve acetate; ethers such as dioxane and tetrahydrofuran; etc. In the case of the mixed solvent, the proportion of the alcohol is, for example, preferably 80% by mass or more, and more preferably 85% by mass or more.

The base catalyst is a catalyst for promoting the reaction (hydrolysis reaction and condensation reaction) of tetraalkoxysilane, and examples thereof include ammonia, urea, monoamine and the like, and ammonia is particularly preferred.

The concentration of the base catalyst in the base catalyst solution is, for example, preferably 0.5mol/L or more and 1.5mol/L or less, more preferably 0.6mol/L or more and 1.2mol/L or less, and still more preferably 0.65mol/L or more and 1.1mol/L or less.

The silica masterbatch production step is a step of producing silica masterbatch by supplying tetraalkoxysilane and a base catalyst to a base catalyst solution, respectively, and allowing the tetraalkoxysilane to react (hydrolysis reaction and condensation reaction) in the base catalyst solution.

In the silica master batch production step, after the core particles are produced by the reaction of the tetraalkoxysilane at the initial stage of the supply of the tetraalkoxysilane (core particle production stage), the silica master batch is produced through the growth of the core particles (core particle growth stage).

Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and the like. From the viewpoints of controllability of reaction rate and uniformity of shape of the silica master batch produced, tetramethoxysilane or tetraethoxysilane is preferable, for example.

Examples of the base catalyst to be supplied to the base catalyst solution include, for example, ammonia, urea, monoamine, and other base catalysts, and ammonia is particularly preferred. The base catalyst to be supplied together with the tetraalkoxysilane and the base catalyst previously contained in the base catalyst solution may be of the same kind or different kinds, but for example, are preferably of the same kind.

The tetraalkoxysilane and the base catalyst may be supplied to the base catalyst solution in a continuous or intermittent manner.

In the silica masterbatch production step, the temperature of the alkali catalyst solution (temperature at the time of supply) is, for example, preferably 5 ℃ or higher and 50 ℃ or lower, and more preferably 15 ℃ or higher and 45 ℃ or lower.

First procedure-

In the first step, for example, a silane coupling agent is added to the silica master batch suspension, and the silane coupling agent is reacted with the surface of the silica master batch to form a coating structure composed of the reaction product of the silane coupling agent.

The reaction of the silane coupling agent is carried out, for example, as follows: after the silane coupling agent is added to the silica master batch suspension, the suspension is heated while stirring. Specifically, for example, the suspension is heated to 40 ℃ or higher and 70 ℃ or lower, and a silane coupling agent is added thereto and stirred. The time for continuous stirring is, for example, preferably 10 minutes to 24 hours, more preferably 60 minutes to 420 minutes, and still more preferably 80 minutes to 300 minutes.

Second procedure-

The second step is preferably a step of attaching a molybdenum-containing nitrogen compound to pores of a coating structure formed by a reaction product of a silane coupling agent, for example.

In the second step, for example, a molybdenum-nitrogen-containing compound is added to the silica master batch suspension after the reaction of the silane coupling agent, and the solution is stirred while maintaining the temperature in a temperature range of 20 ℃ to 50 ℃. Here, the molybdenum-nitrogen-containing compound may be added to the silica particle suspension in the form of an alcohol solution containing the molybdenum-nitrogen-containing compound. The alcohol may be the same type as the alcohol contained in the silica master batch suspension or may be different types, but for example, the same type is more preferable. In the alcohol solution containing the molybdenum-nitrogen compound, the concentration of the molybdenum-nitrogen compound is, for example, preferably 0.05 mass% or more and 10 mass% or less, and more preferably 0.1 mass% or more and 6 mass% or less.

Third procedure-

The third step is a step of further attaching a hydrophobizing structure to a coating structure composed of a reaction product of a silane coupling agent. The third step is a hydrophobization step performed after or during the second step. The hydrophobizing agent forms a hydrophobized layer by reacting functional groups of the hydrophobizing agent with each other and/or with OH groups of the silica master batch.

In the third step, for example, a molybdenum-nitrogen-containing compound is added to the silica master batch suspension after the reaction of the silane coupling agent, followed by the addition of the hydrophobizing agent. In this case, for example, stirring and heating the suspension are preferable. For example, the suspension is heated to 40 ℃ or higher and 70 ℃ or lower, and a hydrophobizing agent is added thereto and stirred. The time for continuous stirring is, for example, preferably 10 minutes to 24 hours, more preferably 20 minutes to 120 minutes, still more preferably 20 minutes to 90 minutes.

Drying procedure-

For example, it is preferable to perform the drying step of removing the solvent from the suspension after the second step or the third step is performed or during the second step or the third step is performed. Examples of the drying method include thermal drying, spray drying, and supercritical drying.

Spray drying can be performed by a known method using a spray dryer (disk rotation type, nozzle type, etc.). For example, the silica particle suspension is sprayed in a hot air stream at a rate of 0.2 liters/hour or more and 1 liter/hour or less. The temperature of the hot air is preferably in the range of, for example, 70 ℃ to 400 ℃ inclusive, and 40 ℃ to 120 ℃ inclusive, of the inlet temperature of the spray dryer. More preferably, the inlet temperature is, for example, in the range of 100℃or more and 300℃or less. The silica particle concentration of the silica particle suspension is preferably, for example, 10 mass% or more and 30 mass% or less.

Examples of the supercritical fluid used for supercritical drying include carbon dioxide, water, methanol, ethanol, and acetone. As the supercritical fluid, supercritical carbon dioxide is preferable from the viewpoint of treatment efficiency and the viewpoint of suppressing generation of coarse particles, for example. Specifically, the step of using supercritical carbon dioxide is performed, for example, by the following operations.

The suspension is contained in a closed reactor, and after liquefied carbon dioxide is introduced, the closed reactor is heated, and the inside of the closed reactor is pressurized by a high-pressure pump, whereby the carbon dioxide in the closed reactor is brought into a supercritical state. Then, the liquefied carbon dioxide is flowed into the closed reactor, and the supercritical carbon dioxide is flowed out of the closed reactor, whereby the supercritical carbon dioxide is circulated into the suspension in the closed reactor. During the circulation of supercritical carbon dioxide into the suspension, the solvent is dissolved in the supercritical carbon dioxide, and the solvent is removed together with the supercritical carbon dioxide flowing out of the closed reactor. The temperature and pressure in the closed reactor are set to a temperature and pressure at which carbon dioxide becomes supercritical. When the critical point of carbon dioxide is 31.1 ℃/7.38MPa, the temperature and pressure are set to, for example, 40 ℃ to 200 ℃ and below/10 MPa to 30 MPa. The flow rate of the supercritical fluid flowing into the closed reactor is preferably, for example, 80 mL/sec or more and 240 mL/sec or less.

For example, it is preferable to decompose and pulverize the obtained silica particles or screen them to remove coarse particles or aggregates. The decomposition and pulverization are performed by a dry pulverizing device such as a jet mill, a vibration mill, a ball mill, and a pin mill. The sieving is performed by, for example, a vibrating screen, a pneumatic sieving machine, or the like.

[ silica particles (B) ]

The toner according to the present embodiment preferably contains silica particles other than the silica particles (a), for example. In the present invention, silica particles other than the silica particles (a) are referred to as silica particles (B).

The silica particles (B) may have a nitrogen-containing element compound containing molybdenum element, in which case the Net intensity N of the molybdenum element is measured by fluorescent X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si Less than 0.035 or more than 0.45.

The silica particles (B) are preferably silica particles containing no nitrogen element compound containing molybdenum element, for example.

As the silica particles (B), for example, hydrophobic silica particles (B) in which the surfaces of silica particles such as sol-gel silica, hydrocolloid silica, alcoholic silica, fumed silica, and fused silica are surface-treated with a hydrophobizing agent (for example, hexamethyldisilazane, a silane-based coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, and silicone oil) are preferable.

The toner according to the present embodiment preferably contains, for example, at least oil-surface-treated silica particles (B). The silica particles function as a supply source for supplying the free oil to the toner. Details of the free oil will be set forth later.

Examples of the oil-surface-treated silica particles (B) include silicone oil, paraffin oil, fluorine oil, vegetable oil, and the like, preferably silicone oil, and more preferably dimethicone (i.e., dimethylpolysiloxane). That is, as the surface-treated silica particles (B) with oil, for example, surface-treated silica particles (B) with silicone oil are preferable, and surface-treated silica particles (B) with dimethicone (i.e., dimethylpolysiloxane) are more preferable.

The external addition amount of the oil-surface-treated silica particles (B) is, for example, preferably 0.3 parts by mass or more and 3.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the toner particles.

The external addition amount of the surface-treated silica particles (B) of the simethicone is, for example, preferably 0.3 parts by mass or more and 3.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the toner particles.

The toner according to the present embodiment may contain a plurality of (for example, two or three) silica particles (B) having different types of the hydrophobizing agent. As an example of the form of the toner, there is a toner containing surface-treated silica particles (B) of hexamethyldisilazane and surface-treated silica particles (B) of silicone oil; a toner containing surface-treated silica particles (B) having a silane coupling agent and surface-treated silica particles (B) having a silicone oil; toner containing surface-treated silica particles (B) with hexamethyldisilazane, surface-treated silica particles (B) with a silane coupling agent, and surface-treated silica particles (B) with silicone oil; etc.

From the viewpoint of difficulty in moving on the toner particle surface, the average roundness of the silica particles (B) is, for example, preferably 0.78 to 0.93, more preferably 0.79 to 0.91, still more preferably 0.80 to 0.90.

In the case where the toner according to the present embodiment contains plural kinds of silica particles (B) having different kinds of the hydrophobizing agent, for example, it is preferable that each of the silica particles (B) is in the above-described range.

The average roundness of the silica particles (B) represents the roundness when the roundness is accumulated to 50% from the small value side in the distribution of the roundness. Roundness is based on the area and perimeter of each primary particle image by: roundness=4pi× (area of particle image)/(circumference of particle image) ² To calculate.

The primary particle diameter distribution of the silica particles (B) may be unimodal, bimodal, or multimodal (e.g., trimodal).

When the distribution of the primary particle diameter of the silica particles (B) is unimodal, the value of the primary particle diameter of the peak is, for example, preferably 20nm to 150nm, more preferably 30nm to 140nm, still more preferably 40nm to 130 nm.

When the distribution of the primary particle diameter of the silica particles (B) is bimodal, the value of the primary particle diameter of the small-diameter side peak is, for example, preferably 20nm or more and less than 80nm, more preferably 30nm or more and 70nm or less, still more preferably 40nm or more and 60nm or less; the primary particle diameter of the large-diameter side peak is preferably 80nm to 150nm, more preferably 90nm to 140nm, and still more preferably 100nm to 130 nm.

The toner according to the present embodiment preferably has at least one peak in a region of the primary particle diameter of 80nm to 150nm in the distribution of the primary particle diameter of the silica particles (B), for example. This means that the toner contains silica particles (B) having a relatively large particle diameter. The silica particles (B) having a relatively large particle diameter function as spacers between toner particles, and thus inhibit aggregation of the toner particles.

The external addition amount of the silica particles (B) forming one peak in the region of the primary particle diameter of 80nm or more and 150nm or less is, for example, preferably 0.3 parts by mass or more and 3.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the toner particles.

When the amount of the silica particles (B) added to the toner is within the above range, which forms one peak in the region of the primary particle diameter of 80nm or more and 150nm or less, the deterioration of the cleaning property due to the insufficient strength of the cleaning dam can be suppressed, and there is an advantage that the adhesion between toners does not become excessively high.

The particle size distribution of the silica particles (B) was obtained as follows.

Using an energy-dispersive X-ray apparatus (EDX apparatus) (80 mm, manufactured by HORIBA, ltd., EMAX Evolution X-Max) ² ) Scanning Electron Microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, S-4800) photographs toner at a magnification of 4 ten thousand times. By EDX analysis, 1000 silica particles (B) which are silica particles other than the silica particles (a) were determined from one field of view, excluding the silica particles (a) according to the presence of Mo element, N element, and Si element. Images of 1000 silica particles (B) were analyzed by image processing analysis software WinRoof (MITANI CORPORATION). The circle equivalent diameter of each primary particle image was obtained, and a histogram was created from the small diameter side of the circle equivalent diameter.

The average primary particle diameter represents the equivalent diameter when the cumulative number is 50% from the small diameter side in the distribution of equivalent diameter. When the distribution of primary particle diameters is bimodal, the average primary particle diameter can be obtained for each peak.

The total external addition amount of the silica particles (B) is, for example, preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 8 parts by mass or less, and still more preferably 2 parts by mass or more and 6 parts by mass or less, relative to 100 parts by mass of the toner particles.

[ strontium titanate particles ]

In order to further suppress occurrence of color streaks, for example, the toner according to the present embodiment is preferably additionally added with strontium titanate particles. The strontium titanate particles scrape fatty acid metal salts that form a film on the surface of the image-holding body, refreshing the surface of the image-holding body. The deteriorated fatty acid metal salt peeled off from the surface of the image holding body is removed by the cleaning blade together with the silica particles (a) functioning as a cleaning aid. Therefore, the image holder and the color streaks generated in the image can be suppressed.

The average primary particle diameter of the strontium titanate particles is, for example, preferably 200nm or more, more preferably 300nm or more, and still more preferably 500nm or more, from the viewpoint of exhibiting a polishing effect on the film-formed fatty acid metal salt.

The average primary particle diameter of the strontium titanate particles is, for example, preferably 2 μm or less, more preferably 1.8 μm or less, and still more preferably 1.5 μm or less, from the viewpoint of less possibility of damaging the image holder cleaning blade.

The average primary particle diameter of the strontium titanate particles was determined by the following measurement method.

Using an energy-dispersive X-ray apparatus (EDX apparatus) (80 mm, manufactured by HORIBA, ltd., EMAX Evolution X-Max) ² ) Scanning Electron Microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, S-4800) photographs a toner containing strontium titanate particles at a magnification of 4 ten thousand times. By EDX analysis, primary particles of 300 or more strontium titanate particles were determined based on the presence of Ti element and Sr element. SEM was observed at an acceleration voltage of 15kV and an emission current of 20 mu A, WD mm, and EDX analysis was performed under the same conditions with a detection time of 60 minutes. The determined strontium titanate particles were analyzed by image processing analysis software WinRoof (MITANI CORPORATION) to determine the circle equivalent diameter of each primary particle image. In the distribution of the circle-equivalent diameters, the small diameter side will accumulateThe equivalent diameter of circle at 50% is calculated as the average primary particle diameter.

The average primary particle diameter of the strontium titanate particles can be controlled, for example, according to various conditions in the production of the strontium titanate particles.

The average primary particle diameter of the strontium titanate particles is preferably smaller than the volume average particle diameter of the toner particles, for example, from the viewpoint that the toner particles are easily detached from the image holder and are not easily transferred to the intermediate transfer member.

The strontium titanate particles are preferably undoped titanium and a metal element other than strontium (hereinafter, also referred to as a dopant). The strontium titanate particles containing no dopant have high crystallinity of perovskite structure and excellent polishing effect on the film-formed fatty acid metal salt.

The shape of the strontium titanate particles is not particularly limited, but is preferably a polyhedron, an irregular shape, a agglomerate or the like, not a shape having sharp corners such as a cube, from the viewpoint of excellent polishing action on the film-formed fatty acid metal salt.

The method for producing the strontium titanate particles is not limited. The strontium titanate particles can be produced by a known production method such as a solid phase method or a wet method. As the solid phase method, for example, a method of mixing titanium oxide and other metal oxides or other metal carbonates and calcining them is known. As a wet method, for example, a method of reacting meta-titanic acid (a hydrate of titanium oxide) with another metal oxide or another metal carbonate in an aqueous system and then drying or calcining the resultant is known; the so-called oxalic acid method is a method for producing strontium titanate by calcining after the formation of oxalate.

From the viewpoint of excellent polishing action on the film-formed fatty acid metal salt, the strontium titanate particles are preferably, for example, strontium titanate particles produced by a wet process.

From the viewpoint of excellent polishing action on the film-formed fatty acid metal salt, the strontium titanate particles are preferably, for example, strontium titanate particles whose surfaces have not been subjected to hydrophobization treatment.

The volume specific resistivity R (Ω·cm) of the strontium titanate particles is, for example, preferably 5 to 10, more preferably 6 to 10, still more preferably 7.5 to 9.5, in terms of a usual log ra.

The volume resistivity R of the strontium titanate particles was measured as follows.

In a pair of 20cm connected to an electrometer (KEITHLEY 610C, manufactured by KEITHLEY Co., ltd.) and a high-voltage power supply (FLUKE 415B, manufactured by Fluke Corporation) ² Strontium titanate particles are placed on the lower electrode plate of the circular electrode plate (steel) measuring jig to form a flat layer having a thickness of 1mm or more and 2mm or less. Subsequently, humidity control was performed at a temperature of 22℃and a relative humidity of 55% for 24 hours. Next, an upper electrode plate was placed on the strontium titanate particle layer in an environment having a temperature of 22 ℃/55% relative humidity, and a weight of 4kg was placed on the upper electrode plate to eliminate voids in the strontium titanate particle layer, and the thickness of the strontium titanate particle layer was measured in this state. Next, a voltage of 1000V was applied to both the electrode plates, and the current value was measured, and the volume resistivity R was calculated according to the following formula (1).

Formula (1): volume specific resistivity R (Ω·cm) =v×s ≡ (A1-A0) ≡d

In the formula (1), V is the applied voltage of 1000 (V), S is the plate area of 20 (cm) ² ) A1 is a measured current value (a), A0 is an initial current value (a) when a voltage of 0V is applied, and d is a thickness (cm) of the strontium titanate particle layer.

From the viewpoint of obtaining the effect of the strontium titanate particles, the external addition amount of the strontium titanate particles is, for example, preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and still more preferably 0.02 parts by mass or more with respect to 100 parts by mass of the toner particles.

The external addition amount of the strontium titanate particles is, for example, preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and still more preferably 0.3 parts by mass or less, relative to 100 parts by mass of the toner particles, from the viewpoint of not damaging the image holder cleaning blade.

The ratio M3/M1 of the mass basis of the content M1 of the fatty acid metal salt particles and the content M3 of the strontium titanate particles contained in the toner is, for example, preferably 0.1 to 2.0, more preferably 0.3 to 1.8, still more preferably 0.5 to 1.5.

When the ratio M3/M1 is 0.1 or more, the effect of scraping the fatty acid metal salt formed on the surface of the image holder by the strontium titanate particles is further exerted, and the surface of the image holder is more easily refreshed.

When the ratio M3/M1 is 2.0 or less, the film of the fatty acid metal salt is maintained on the surface of the image holder, and the lubricating effect of the fatty acid metal salt is sufficiently exhibited.

[ other external additives ]

The toner according to the present embodiment may be additionally provided with an external additive other than the fatty acid metal salt particles, the silica particles (a), the silica particles (B), and the strontium titanate particles. Examples of other external additives include TiO ₂ 、Al ₂ O ₃ 、CuO、ZnO、SnO ₂ 、CeO ₂ 、Fe ₂ O ₃ 、MgO、BaO、CaO、K ₂ O、Na ₂ O、ZrO ₂ 、CaO·SiO ₂ 、K ₂ O·(TiO ₂ ) _n 、Al ₂ O ₃ ·2SiO ₂ 、CaCO ₃ 、MgCO ₃ 、BaSO ₄ 、MgSO ₄ Inorganic particles; surface-treated hydrophobized inorganic particles of these inorganic particles with a hydrophobizing agent; resin particles such as polystyrene, polymethyl methacrylate, and melamine resin; etc.

[ free oil ]

An example of the embodiment of the toner according to the present embodiment contains free oil. The free oil contained in the toner may be an oil added in the form of an external additive or may be an oil free from particles as an external additive. From the viewpoint of easy adjustment of the content of the free oil, for example, it is preferable to add the oil-treated particles to the toner so that the toner contains the free oil.

Examples of the free oil include silicone oil, paraffin oil, fluorine oil, vegetable oil, and the like. The free oil may be one kind or plural kinds. Among them, for example, silicone oil is preferable, and simethicone (i.e., dimethylpolysiloxane) is more preferable.

From the viewpoint of suppressing aggregation of the toner and suppressing occurrence of color streaks, the content of the free oil is, for example, preferably 0.01% by mass or more and 0.1% by mass or less, more preferably 0.03% by mass or more and 0.08% by mass or less, and still more preferably 0.05% by mass or more and 0.07% by mass or less, relative to the entire toner. When the content of the free oil is within the above range, a decrease in the cleaning property due to insufficient strength of the cleaning dam can be suppressed, and there is an advantage in that the adhesion between toners does not become excessively high.

The free oil amount (%) relative to the entire toner was obtained by the following method.

The toner externally added with the external additive was dispersed in hexane so that the toner concentration became 5 mass%, ultrasonic waves (output 20W, frequency 20 kHz) were applied for 20 minutes, and the supernatant and the solid components were centrifugally separated. When the mass of the toner as a sample is Wb and the solid component amount after centrifugal separation is Wa, the free oil amount (%) with respect to the whole toner is represented by the following formula.

Free oil amount (%) = (Wb-Wa)/(wb×100)

Examples of the oil-treated particles include oil-treated inorganic particles (SiO ₂ 、TiO ₂ 、Al ₂ O ₃ 、CuO、ZnO、SnO ₂ 、CeO ₂ 、Fe ₂ O ₃ 、MgO、BaO、CaO、K ₂ O、Na ₂ O、ZrO ₂ 、CaO·SiO ₂ 、K ₂ O·(TiO ₂ ) _n 、Al ₂ O ₃ ·2SiO ₂ 、CaCO ₃ 、MgCO ₃ 、BaSO ₄ 、MgSO ₄ Etc.), oil-treated resin particles (resin particles such as polystyrene, polymethyl methacrylate, melamine resin, etc.). As the oil-treated particles, for example, oil-treated silica particles are preferable.

The oil treatment of the particles is performed, for example, by mixing the organic solvent, the particles, and the oil with stirring, then distilling off the organic solvent using an evaporator, and drying the mixture. Examples of the oil include silicone oil, paraffin oil, fluorine oil, and vegetable oil, and among them, silicone oil is preferable, and dimethylsilicone (i.e., dimethylpolysiloxane) is more preferable.

The amount of free oil in the oil-treated particles was measured by the following method.

The oil-treated particles were dispersed in hexane so that the concentration became 5 mass%, ultrasonic waves (output 20W, frequency 20 kHz) were applied for 20 minutes, and the supernatant and the solid components were centrifugally separated. When the mass of the oil-treated particles as the sample is Wb and the solid component amount after centrifugation is Wa, the free oil amount (mass%) in the oil-treated particles is represented by the following formula.

Free oil amount (mass%) = (Wb-Wa)/(wb×100)

[ Structure and Properties of toner ]

Relationship between toner particles and external additives

The ratio Dp/Da of the average particle diameter of the resin particles contained in the toner particles (referred to as "average particle diameter Dp" in the present invention) to the average primary particle diameter of the silica particles (a) externally added to the toner particles (referred to as "average primary particle diameter Da" in the present invention) is preferably, for example, 0.75 to 15.

If the ratio Dp/Da is 15 or less, the silica particles (a) are less likely to be buried in the resin particles contained in the toner particles. From this viewpoint, the ratio Dp/Da is, for example, preferably 10 or less, and more preferably 5 or less.

When the ratio Dp/Da is 0.75 or more, the silica particles (a) are less likely to be buried in the binder resin contained in the toner particles. From this viewpoint, the ratio Dp/Da is, for example, preferably 1.0 or more, and more preferably 1.5 or more.

For example, the method and preferable range for measuring the average particle diameter of the resin particles and the method and preferable range for measuring the average primary particle diameter of the silica particles (a) are as described above.

From the viewpoint of coating the toner particle surface with a highly uniform and appropriate coating ratio, the surface coating ratio (referred to as "surface coating ratio C1" in the present invention) of the silica particles (a) coating the toner particles is, for example, preferably 10% or more and 60% or less, more preferably 15% or more and 55% or less, and still more preferably 20% or more and 50% or less.

When the toner according to the present embodiment contains silica particles other than the silica particles (a), the ratio C1/C2 of the surface coating ratio (referred to as "surface coating ratio C1" in the present invention) of the silica particles (a) to the surface coating ratio (referred to as "surface coating ratio C2" in the present invention) of the silica particles (a) to the silica particles having a primary particle diameter of 80nm or more and 150nm or less to the silica particles (a) is preferably, for example, 0.2 or more and 1.5 or less.

When the ratio C1/C2 is within the above range, the silica particles (a) and the silica particles having a primary particle diameter of 80nm or more and 150nm or less are uniformly dispersed and present on the toner particle surface, whereby the silica particles functioning as spacers between toner particles are uniformly distributed on the toner particle surface, and therefore aggregation of toner can be suppressed.

From the above point of view, the ratio C1/C2 is, for example, more preferably 0.4 to 1.2, and still more preferably 0.6 to 1.0.

The surface coating ratio C1 and the surface coating ratio C2 were measured as follows.

Using an energy-dispersive X-ray apparatus (EDX apparatus) (80 mm, manufactured by HORIBA, ltd., EMAX Evolution X-Max) ² ) Scanning Electron Microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, S-4800) photographs the entire toner at a magnification of 4 ten thousand times. The external additive present on the surface of one toner is classified into silica particles (a) and silica particles other than the silica particles (a) by EDX analysis based on the presence of Mo element, N element, and Si element. Further, silica particles having a circular equivalent diameter of 80nm or more and 150nm or less are extracted from silica particles other than the silica particles (A).

The image of one toner is analyzed by the image processing analysis software WinRoof (MITANI CORPORATION), and the area of one toner, the total area of the silica particles (a) present in one toner, and the total area of the silica particles having a circular equivalent diameter of 80nm to 150nm inclusive, other than the silica particles (a) present in one toner, are obtained. The image analysis was performed on 100 toners to determine the total area of 100 toners, the total area of silica particles (a) present in 100 toners, and the total area of silica particles having a circular equivalent diameter of 80nm to 150nm inclusive, excluding silica particles (a) present in 100 toners. The surface coating ratio C1 and the surface coating ratio C2 were calculated according to the following formula.

Surface coating ratio c1 (%) = (total area of silica particles (a) present in 100 toners/total area of 100 toners) ×100

Surface coating ratio c2 (%) = (total area of silica particles having a circular equivalent diameter of 80nm or more and 150nm or less excluding silica particles (a) present in 100 toners per total area of 100 toners) ×100

Viscoelasticity of the toner

In the dynamic viscoelasticity measurement, when the loss tangent tan δ at 90 ℃ and strain amount of 1% is D1 (90), the loss tangent tan δ at 90 ℃ and strain amount of 50% is D50 (90), the loss tangent tan δ at 150 ℃ and strain amount of 1% is D1 (150), and the loss tangent tan δ at 150 ℃ and strain amount of 50% is D50 (150), the toner according to the present embodiment is preferably:

d50 A value of (150) -D1 (150) of less than 1.5, and

d50 The value of (90) -D1 (90) is less than 1.0.

D1 (90), D50 (90), D1 (150) and D50 (150) of the toner were obtained by the following measurement methods.

The toner was molded into a sheet shape by a compression molding machine at room temperature (25 ℃ ±3 ℃) to prepare a test sample. The measurement sample was sandwiched between parallel plates having a diameter of 8mm, and dynamic viscoelasticity was measured at a gap of 3mm, a frequency of 1Hz, a strain amount of 1% or 50%, and a temperature of 90℃or 150℃using a dynamic viscoelasticity measuring apparatus (Rheometer ARES-G2, manufactured by TA Instruments Co., ltd.) to obtain curves of storage elastic modulus and loss elastic modulus, and the loss tangent tan. Delta. Was obtained.

Here, the strain amount of 1% in the dynamic viscoelasticity measurement means a displacement of 1% with respect to the height (i.e., gap) of the sample. That is, the application of displacement with a strain amount of 1% being very small corresponds to the case where the fixer pressure is low in the fixing process of the toner. On the other hand, the strain amount of 50% corresponds to a case where the fixer pressure is high in the fixing process of the toner. The temperature of 90 ℃ and the strain amount of 1% correspond to the fixing conditions at low temperature and low pressure, the temperature of 150 ℃ and the strain amount of 50% correspond to the fixing conditions at high temperature and high pressure, and the loss tangent tan δ corresponds to the toner deformation amount under each fixing condition. It is estimated that by controlling the difference between the loss tangent tan delta at the strain amount of 1% and the loss tangent tan delta at the strain amount of 50% to be within a predetermined range, even when the fixer pressure is changed, the deformation amount of the toner can be suppressed to be within a predetermined range, thereby suppressing the difference in glossiness.

The above measurement method was carried out at a combination of high temperature (150 ℃), low temperature (90 ℃) and high strain (50%) and low strain (1%) to obtain the loss tangent tan δ. If the measurement temperature is too low, it is difficult to exhibit viscoelastic properties, and thus the measurement is performed at 150℃and 90 ℃.

Since the toner according to the present embodiment has the dynamic viscoelasticity, the external additive is not easily buried even when the toner is subjected to a strong mechanical stress in a high-temperature and high-humidity environment. Therefore, the toner according to the present embodiment is less likely to generate color streaks because of the dynamic viscoelasticity.

Further, since the dynamic viscoelasticity characteristic described above is provided, the toner according to the present embodiment exhibits good fixability, and at the same time, the difference in glossiness between the fixed image under low-temperature low-pressure conditions and the fixed image under high-temperature high-pressure conditions can be reduced. The reason is presumed to be as follows.

Toner that is easily melted by heating generally has good fixability. However, the difference in glossiness of a fixed image of an image formed of toner that is easily melted by heating may increase depending on the fixing conditions.

In contrast, the toner having dynamic viscoelasticity characteristics according to the present embodiment has a small change in loss tangent with respect to a change in strain amount at 90 ℃ or 150 ℃. It is presumed that since the toner has near viscoelasticity under high temperature and high strain conditions and low temperature and low strain conditions, the difference in glossiness of the fixed image according to the fixing conditions is small.

In the present embodiment, since D1 (90), D50 (90), D1 (150) and D50 (150) are all 0.5 or more, they are easily melted by heating during fixing, and good fixability can be obtained, compared with the case where any of them is less than 0.5.

D1 The values of (90), D50 (90), D1 (150) and D50 (150) are, for example, preferably 0.5 to 2.5, more preferably 0.5 to 2.0, still more preferably 0.6 to 1.8, and still more preferably 0.8 to 1.6, respectively. When D1 (90), D50 (90), D1 (150) and D50 (150) are each within the above range, good fixability can be obtained as compared with the case where D is smaller than the above range, and the difference in glossiness can be reduced as compared with the case where D is larger than the above range.

D50 The value of (150) -D1 (150) is, for example, preferably less than 1.5, more preferably 1.2 or less, and further preferably 1.0 or less. The value of D50 (150) -D1 (150) falls within the above range, and the difference in glossiness is reduced as compared with the case where it is larger than the above range. From the viewpoint of reducing the difference in glossiness, the smaller the values of D50 (150) -D1 (150), for example, the more preferable. D50 The lower limit of (150) -D1 (150) is not limited.

D50 The value of (90) -D1 (90) is, for example, preferably less than 1.0, more preferably less than 0.5, more preferably 0.4 or less, and further preferably 0.3 or less. By the values of D50 (90) -D1 (90) being within the above range, the difference in glossiness is reduced as compared with the case where it is larger than the above range. From the viewpoint of reducing the difference in glossiness, the smaller the values of D50 (90) -D1 (90), for example, the more preferable. D50 The lower limit of (90) -D1 (90) is not limited.

For example, in the dynamic viscoelasticity measurement in which the temperature is raised at a rate of 2 ℃/min, the toner according to the present embodiment preferably has a storage elastic modulus G' of 1×10 in a range of 30 ℃ to 50 ℃ ⁸ Pa or more and less than 1×10 ⁵ The storage elastic modulus G' of Pa is 65 ℃ or higher and 90 DEG CBelow c. The toner having the present characteristic has a high elastic modulus at low temperature, and has a low elastic modulus at 65 ℃ or more and 90 ℃ or less. Toners having the present characteristics are less than 1X 10 as compared to ⁵ When the temperature at which the storage elastic modulus G' of Pa exceeds 90 ℃, the toner is easily melted by heating, and the fixability is good.

In the toner according to the present embodiment, for example, in dynamic viscoelasticity measurement in which the temperature rises at a rate of 2 ℃/min, the storage elastic modulus G' of 30 ℃ or more and 50 ℃ or less is preferably 1×10 ⁸ Pa or more, more preferably 1×10 ⁸ Pa or more and 1×10 ⁹ Pa, more preferably 2X 10 ⁸ Pa or more and 6×10 ⁸ Pa or below. The toner having the present characteristic has both storage stability and good fixability.

For example, in the dynamic viscoelasticity measurement in which the temperature rises at a rate of 2 ℃/min, the toner according to the present embodiment preferably has a temperature of less than 1×10 ⁵ The temperature at which the storage elastic modulus G' of Pa is set is 65℃to 90℃inclusive, more preferably 70℃to 87℃inclusive, still more preferably 75℃to 84℃inclusive. The toner having the present characteristic has both storage stability and good fixability.

Storage modulus G' and up to less than 1X 10 of toner ⁵ The temperature at which the storage elastic modulus G' of Pa was measured was determined by the following measurement method.

The toner was molded into a sheet shape by a compression molding machine at room temperature (25 ℃ ±3 ℃) to prepare a test sample. The measurement sample was sandwiched between parallel plates having a diameter of 8mm, and the dynamic viscoelasticity was measured by heating the sample from 30℃to 150℃at a rate of 2℃per minute with a gap of 3mm and a frequency of 1Hz and a strain of 0.1% to 100% by using a dynamic viscoelasticity measuring apparatus (Rheometer ARES-G2, manufactured by TA Instruments). From the curve of the storage modulus of elasticity obtained by the measurement, the storage modulus of elasticity G' is determined and reaches less than 1X 10 ⁵ Temperature at which the storage modulus G' of Pa is maintained.

The viscoelastic properties can be controlled according to the type and dispersion of the resin particles contained in the toner particles. For example, the viscoelastic characteristics are achieved by uniformly containing resin particles (for example, preferably resin particles (S)) in both the region near the surface of the toner particles and the region near the center of the toner particles.

In order to contain the resin particles in the toner particles, for example, the resin particles preferably have high affinity with the binder resin. Examples of the method for improving the affinity of the two include controlling the SP value and using a surfactant as a dispersant for the resin particles.

However, unlike inorganic particles, carbon black, metal particles, and the like, since the resin particles are composed of an organic polymer, the resin particles having high affinity with the binder resin are easily compatible with the binder resin, and the dispersibility in the toner particles may be low. On the other hand, resin particles having low affinity with the binder resin are not likely to be contained in the toner particles, and may be discharged to the surface of the toner particles or outside the toner particles. Resin particles having a moderate affinity for the binder resin are easily contained and dispersed in the toner particles.

On the other hand, when resin particles come into contact with each other in the process of producing toner particles, the resin particles may be unevenly dispersed in the toner particles while maintaining a state of contact with each other. One of the reasons for this is considered entanglement of polymer chains of the resin constituting the resin particles. If the resin particles are crosslinked resin particles, the polymer chains of the resin are less likely to be entangled, and the resin particles are less likely to remain in contact with each other, so that the resin particles are easily and uniformly arranged in the toner particles.

The toner according to the present embodiment preferably has a number average molecular weight of a Tetrahydrofuran (THF) -soluble component of toner particles of 5000 or more and 15000 or less, for example. In this range, the change in loss tangent with respect to the change in strain amount is small, that is, even in the toner having high viscoelasticity in which the deformation amount is suppressed, good fixability can be achieved. In the case where the number average molecular weight of THF soluble components of the toner particles is excessively small, since a large amount of low molecular weight components are present in the toner, the deformation amount of the toner particles increases under high-temperature high-pressure fixing conditions, resulting in a tendency for the difference in glossiness of the image to increase. In the case where the number average molecular weight of THF soluble components of the toner particles is excessively large, since a large amount of high molecular weight components are present in the toner, the low temperature fixability tends to be deteriorated although the deformation amount of the toner is suppressed. The number average molecular weight of THF soluble components of the toner particles is more preferably 7000 or more and 10000 or less, for example.

The number average molecular weight of the THF-soluble component in the toner particles was measured using two "HLC-8120GPC, SC-8020 (TOSOH CORPORATION, 6.0 mmID. Times.15 cm)", wherein Tetrahydrofuran (THF) was used as an eluent to prepare the THF-soluble component of the toner particles.

Specifically, 0.5mg of toner particles to be measured was dissolved in 1g of THF, and after ultrasonic dispersion was applied, the concentration was set to 0.5 mass%.

The measurement was performed using an RI detector under conditions of a sample concentration of 0.5 mass%, a flow rate of 0.6ml/min, a sample injection amount of 10. Mu.l, and a measurement temperature of 40 ℃.

Calibration curves were prepared according to the "Polystyrene Standard sample TSK Standard" manufactured by TOSOH CORPORATION: 10 samples of "A-500", "F-1", "F-10", "F-80", "F-380", "A-2500", "F-4", "F-40", "F-128", "F-700" were made.

When toner particles are obtained from externally added toner, for example, the toner is dispersed in an aqueous solution of 0.2 mass% of polyoxyethylene (10) octylphenyl ether so as to be 10 mass%, and ultrasonic vibration (frequency 20kHz, output 30W) is applied for 60 minutes while maintaining a temperature of 30 ℃ or lower, whereby the external additive is released. The toner particles are filtered out of the obtained dispersion liquid, and washed, thereby obtaining toner particles from which the external additive is removed.

[ method for producing toner ]

The toner according to the present embodiment is obtained by adding an external additive to the toner particles after the toner particles are produced.

The toner particles can be produced by any one of a dry process (for example, a kneading and pulverizing process) and a wet process (for example, an aggregation process, a suspension polymerization process, a dissolution suspension process, and the like). These methods are not limited, and known methods can be used. Among them, for example, toner particles are preferably obtained by a gel aggregation method.

Specifically, for example, in the case of producing toner particles by the aggregate method, the toner particles are produced by the following steps:

a step (resin particle dispersion preparation step) of preparing a resin particle dispersion (1) in which resin particles (1) are dispersed and a resin particle dispersion (2) in which resin particles (2) are dispersed, which are binder resins;

a step (aggregate particle forming step) of forming aggregate particles by aggregating the resin particles (1) and the resin particles (2) (and optionally, other particles) in a dispersion obtained by mixing the resin particle dispersion (1) and the resin particle dispersion (2) (in a dispersion obtained by mixing other particle dispersions as needed); and

And a step (fusion/fusion step) of heating the aggregated particle dispersion liquid in which the aggregated particles are dispersed to fuse/fuse the aggregated particles and form toner particles.

Details of each step will be described below.

In the following description, a method of obtaining toner particles containing a colorant and a release agent is described, but the colorant and the release agent are used as needed. Of course, other additives besides colorants and mold release agents may be used.

Preparation of resin particle Dispersion

The resin particle dispersion (1) is produced, for example, by dispersing the resin particles (1) in a dispersion medium using a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid (1) include aqueous media.

Examples of the aqueous medium include distilled water, deionized water, and other water and alcohols. One kind of them may be used alone, or two or more kinds may be used simultaneously.

Examples of the surfactant include anionic surfactants such as sulfate salts, sulfonate salts, phosphate esters, and soaps; amine salt type and quaternary ammonium salt type cationic surfactants; nonionic surfactants such as polyethylene glycol-based, alkylphenol-ethylene oxide-based adducts and polyhydric alcohols-based surfactants. Among them, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used together with an anionic surfactant or a cationic surfactant. The surfactant may be used alone or in combination of two or more.

In the resin particle dispersion (1), as a method of dispersing the resin particles (1) in a dispersion medium, for example, a general dispersion method such as a rotary shear type homogenizer, a ball MILL with a medium, a sand MILL, and a DYNO-MILL can be cited. Depending on the type of the resin particles (1), the resin particles (1) may be dispersed in a dispersion medium by a phase inversion emulsification method. The phase inversion emulsification method is as follows: the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and after neutralization by adding a base to an organic continuous phase (O phase), an aqueous medium (W phase) is introduced, whereby the phase is changed from W/O to O/W, and the resin is dispersed in the aqueous medium in the form of particles.

The volume average particle diameter of the resin particles (1) dispersed in the resin particle dispersion (1) is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and still more preferably 0.1 μm or more and 0.6 μm or less.

Regarding the volume average particle diameter of the resin particles (1), the cumulative distribution of the volume is plotted from the small particle diameter side against the particle size range (channel) divided by the particle size distribution obtained by measurement using a laser diffraction particle size distribution measuring apparatus (for example, HORIBA, ltd. System LA-700), and the particle diameter at which 50% is cumulative with respect to all the particles is measured as the volume average particle diameter D50v. The volume average particle diameter of the particles in the other dispersion was measured in the same manner.

The content of the resin particles (1) contained in the resin particle dispersion (1) is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

In the same manner as the resin particle dispersion (1), for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, the volume average particle diameter, the dispersion medium, the dispersion method, and the content of the particles in the resin particle dispersion (1) are similarly applicable to the colorant particles dispersed in the colorant particle dispersion and the release agent particles dispersed in the release agent particle dispersion.

As a method for producing the resin particle dispersion (2), for example, known methods such as emulsion polymerization, melt kneading using a banbury mixer or kneader, suspension polymerization, and spray drying can be applied. Among them, for example, emulsion polymerization is preferable.

From the viewpoint of keeping the storage modulus G' and the loss tangent tan δ of the resin particles within the preferred ranges, for example, it is preferable to use a styrene-based monomer and a (meth) acrylic monomer as monomers, and emulsion polymerization is performed in the presence of a crosslinking agent. The emulsion polymerization is preferably carried out, for example, in a plurality of times.

The method for producing the resin particle dispersion (2) preferably includes, for example:

a step of obtaining an emulsion containing a monomer, a crosslinking agent, a surfactant and water (emulsion preparation step);

a step of adding a polymerization initiator to the emulsion, and then heating the emulsion to polymerize the monomer (first emulsion polymerization step); and

And a step (second emulsion polymerization step) of adding an emulsion containing a monomer and a crosslinking agent to the reaction solution after the first emulsion polymerization step, and then heating the mixture to polymerize the monomer.

Emulsion preparation procedure

For example, the emulsion is preferably obtained by emulsifying the monomer, the crosslinking agent, the surfactant, and water with an emulsifying machine. Examples of the emulsifying machine include a rotary mixer having propeller-type, anchor-type, paddle-type or turbine-type stirring blades, a static mixer such as a static mixer, a homogenizer, a rotor/stator-type emulsifying machine such as Crea Mix, a high-pressure emulsifying machine such as a grinding-type emulsifying machine having a grinding function, a high-pressure nozzle-type emulsifying machine which generates cavitation at high pressure, a high-pressure collision-type emulsifying machine which applies shear force by causing liquids to collide with each other at high pressure, a ultrasonic emulsifying machine which generates cavitation by ultrasonic waves, and a membrane emulsifying machine which uniformly emulsifies through holes.

As the monomer, for example, a styrene monomer and a (meth) acrylic monomer are preferably used. As the crosslinking agent, the compounds already described can be used.

Examples of the surfactant include anionic surfactants such as sulfate salts, sulfonate salts, phosphate esters, and soaps; amine salt type and quaternary ammonium salt type cationic surfactants; nonionic surfactants such as polyethylene glycol-based, alkylphenol-ethylene oxide-based adducts and polyhydric alcohols-based surfactants. The nonionic surfactant may be used together with an anionic surfactant or a cationic surfactant. Among them, for example, anionic surfactants are preferable. The surfactant may be used alone or in combination of two or more.

The emulsion may contain a chain transfer agent. Examples of the chain transfer agent include compounds having a thiol component. Specifically, for example, alkylthio alcohols such as hexanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol and dodecanethiol are preferable.

From the viewpoint of keeping the storage modulus G' and the loss tangent tan δ of the resin particles within the preferred ranges, the mass ratio of the styrene-based monomer to the (meth) acrylic monomer in the emulsion (styrene-based monomer/(meth) acrylic monomer) is preferably, for example, 0.2 to 1.1. The proportion of the crosslinking agent in the entire emulsion is preferably, for example, 0.5 mass% or more and 3 mass% or less, from the viewpoint of keeping the storage modulus G' and the loss tangent tan δ of the resin particles within the preferable ranges.

First emulsion polymerization Process

The method is a step of adding a polymerization initiator to the emulsion, and then heating the emulsion to polymerize the monomer.

As the polymerization initiator, for example, ammonium persulfate is preferably used. The viscoelasticity of the resin particles can be controlled by adjusting the addition amount of the polymerization initiator. For example, by reducing the amount of the polymerization initiator added, resin particles having a high storage elastic modulus G' can be easily obtained.

When polymerizing the monomers, for example, the emulsion (reaction solution) containing the polymerization initiator is preferably stirred by a stirrer. Examples of the stirrer include a rotary stirrer having propeller-type, anchor-type, paddle-type or turbine-type stirring blades.

Second emulsion polymerization Process

The method is a step of adding an emulsion containing a monomer to a reaction solution after the first emulsion polymerization step, and then heating the mixture to polymerize the monomer. The additional emulsion is preferably obtained by emulsifying the monomer, the surfactant, and water, for example, by an emulsifying machine. In the polymerization, for example, the reaction solution is preferably stirred in the same manner as in the first emulsion polymerization step.

The viscoelasticity of the resin particles can be controlled by adjusting the time taken to add the emulsion containing the monomer. For example, by lengthening the time taken to add the monomer-containing emulsion, resin particles having a high storage elastic modulus G' can be easily obtained. Examples of the time taken to add the monomer-containing emulsion include a range of 2 hours to 5 hours.

The viscoelasticity of the resin particles can be controlled by adjusting the temperature at which the reaction solution is stirred. For example, by lowering the temperature at which the reaction solution is stirred, resin particles having a high storage elastic modulus G' can be easily obtained. The temperature at which the reaction solution is stirred may be, for example, 55℃or more and 75℃or less.

Agglomerated particle formation step

Next, the resin particle dispersion (1), the resin particle dispersion (2), the colorant particle dispersion, and the release agent particle dispersion are mixed. Then, the resin particles (1), the resin particles (2), the colorant particles and the release agent particles are heterogeneous aggregated in the mixed dispersion liquid to form aggregated particles having a diameter close to the diameter of the target toner particles.

Specifically, for example, an aggregating agent is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, the pH is 2 or more and 5 or less), and after adding a dispersion stabilizer as necessary, the mixed dispersion is heated to a temperature close to the glass transition temperature of the resin particles (1) (specifically, for example, the glass transition temperature of the resin particles (1) is from-30 ℃ to-10 ℃ inclusive) to aggregate the particles dispersed in the mixed dispersion, thereby forming aggregated particles. In the agglomerated particle forming step, for example, the mixed dispersion may be stirred by a rotary shear homogenizer, an agglomerating agent may be added at room temperature (for example, 25 ℃) to adjust the pH of the mixed dispersion to be acidic (for example, pH is 2 or more and 5 or less), and a dispersion stabilizer may be added as needed, followed by heating.

The dispersion state of the resin particles in the obtained toner particles can be controlled by adjusting the temperature of the mixed dispersion liquid when the coagulant is added. For example, by lowering the temperature of the mixed dispersion, the dispersibility of the resin particles becomes good. The temperature of the mixed dispersion liquid may be, for example, 5℃to 40 ℃.

The dispersion state of the resin particles in the obtained toner particles can be controlled by adjusting the stirring speed after the addition of the coagulant. For example, by increasing the stirring speed after adding the coagulant, the dispersibility of the resin particles becomes good.

Examples of the aggregating agent include surfactants having a polarity opposite to that of the surfactants contained in the mixed dispersion liquid, inorganic metal salts, and metal complexes having a valence of 2 or more. When the metal complex is used as the coagulant, the amount of the surfactant used can be reduced, and the charging characteristics can be improved.

Additives forming a complex or a similar bond with a metal ion of the coagulant may be used together with the coagulant as needed. As the additive, a chelating agent can be used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; etc.

As the chelating agent, a water-soluble chelating agent can be used. Examples of the chelating agent include hydroxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), ethylenediamine tetraacetic acid (EDTA); etc.

The amount of the chelating agent to be added is, for example, preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to less than 3.0 parts by mass, based on 100 parts by mass of the resin particles.

Fusion/integration procedure

Next, the aggregated particle dispersion liquid in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (1) (for example, a temperature 10 ℃ to 30 ℃ higher than the glass transition temperature of the resin particles (1)), and the aggregated particles are fused and coalesced to form toner particles.

Toner particles were obtained through the above steps.

The toner particles may be produced by the following steps: a step of mixing the resin particle dispersion (1) and the resin particle dispersion (2) with the aggregated particle dispersion to form a 2 nd aggregated particle by allowing the resin particles (1) and the resin particles (2) to adhere to the surfaces of the aggregated particles after obtaining the aggregated particle dispersion; and a step of heating the 2 nd aggregated particle dispersion liquid in which the 2 nd aggregated particles are dispersed, thereby melting/integrating the 2 nd aggregated particles to form toner particles having a core/shell structure.

In the step of forming the 2 nd aggregated particles, the resin particle dispersion liquid (1) and the resin particle dispersion liquid (2) may be added in a plurality of times. Thus, toner particles in which the core particles and the shell layer each contain resin particles in a highly uniform dispersion can be obtained.

After the completion of the melting/combining step, the toner particles in the dispersion are subjected to a known cleaning step, solid-liquid separation step, and drying step to obtain dry toner particles. From the viewpoint of chargeability, the cleaning step is preferably, for example, a replacement cleaning with deionized water is sufficiently performed. From the viewpoint of productivity, the solid-liquid separation step is preferably performed by, for example, suction filtration or pressure filtration. From the viewpoint of productivity, the drying step is preferably performed, for example, freeze drying, air drying, fluidized drying, vibration type fluidized drying, or the like.

The toner according to the present embodiment is produced by adding an external additive to the obtained dry toner particles and mixing the resultant toner particles. The mixing is preferably performed by, for example, a V-mixer, a henschel mixer, a rotundite mixer, or the like. If necessary, coarse particles of the toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

< developer for electrostatic latent image >)

The electrostatic latent image developer according to the present embodiment contains at least the toner according to the present embodiment.

The electrostatic latent image developer according to the present embodiment may be a single-component developer containing only the toner according to the present embodiment, or may be a two-component developer obtained by mixing the toner and a carrier.

The carrier is not particularly limited, and known carriers can be used. Examples of the carrier include a coated carrier in which the surface of a core material made of magnetic powder is coated with a resin; a magnetic powder dispersion type carrier prepared by dispersing a magnetic powder in a matrix resin; a resin-impregnated carrier in which a resin is impregnated into a porous magnetic powder; etc.

The magnetic powder dispersion type carrier and the resin impregnation type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and the surface thereof is coated with a resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; etc.

Examples of the coating resin and the base resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, a vinyl chloride-vinyl acetate copolymer, a styrene acrylate copolymer, a linear silicone resin configured to contain an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenolic resin, an epoxy resin, and the like. The coating resin and the base resin may contain other additives such as conductive particles. Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Examples of the method for coating the surface of the core material with the resin include a method in which the core material is coated with a coating layer-forming solution obtained by dissolving a coating resin and various additives (used as needed) in an appropriate solvent. The solvent is not particularly limited, and may be selected in consideration of the type of resin used, coating suitability, and the like.

Specific examples of the resin coating method include an impregnation method in which the core material is immersed in a coating layer forming solution; spraying a coating layer forming solution on the surface of the core material; a fluidized bed method in which a solution for forming a coating layer is sprayed in a state in which a core material is suspended by flowing air; a kneading coating method in which a core material of a carrier and a coating layer forming solution are mixed in a kneading coater and then a solvent is removed; etc.

The mixing ratio (mass ratio) of the toner to the carrier in the two-component developer is, for example, preferably toner: carrier=1:100 to 30:100, more preferably 3:100 to 20:100.

Image Forming apparatus, image Forming method

An image forming apparatus and an image forming method according to the present embodiment will be described.

The image forming apparatus according to the present embodiment includes: an image holding body; a charging member for charging the surface of the image holding body; an electrostatic latent image forming member that forms an electrostatic latent image on a surface of the charged image holding body; a developing member that accommodates an electrostatic latent image developer and develops the electrostatic latent image formed on the surface of the image holding body into a toner image by the electrostatic latent image developer; a transfer member that transfers the toner image formed on the surface of the image holding body onto the surface of the recording medium; and a fixing member that fixes the toner image transferred onto the surface of the recording medium. The electrostatic latent image developer according to the present embodiment is also applicable as the electrostatic latent image developer.

In the image forming apparatus according to the present embodiment, an image forming method (image forming method according to the present embodiment) including the steps of: a charging step of charging the surface of the image holder; an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged image holder; a developing step of developing an electrostatic latent image formed on the surface of the image holding member into a toner image with the electrostatic latent image developer according to the present embodiment; a transfer step of transferring the toner image formed on the surface of the image holder onto the surface of the recording medium; and a fixing step of fixing the toner image transferred onto the surface of the recording medium.

The image forming apparatus according to the present embodiment is applied to the following known image forming apparatus: a direct transfer system for directly transferring the toner image formed on the surface of the image holder onto a recording medium; an intermediate transfer means for primarily transferring the toner image formed on the surface of the image holding body onto the surface of the intermediate transfer body and secondarily transferring the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium; a device provided with a cleaning member for cleaning the surface of the image holder before charging after transferring the toner image; a device including a charge removing member for irradiating the surface of the image holder with a charge removing light to remove the charge after transferring the toner image; etc.

In the case where the image forming apparatus according to the present embodiment is an intermediate transfer type apparatus, the transfer member is configured to have, for example, the following structure: an intermediate transfer body that transfers the toner image onto a surface; a primary transfer member that primary transfers the toner image formed on the surface of the image holding body onto the surface of the intermediate transfer body; and a secondary transfer member that secondarily transfers the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing member may be a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge having a developing member that accommodates the electrostatic latent image developer according to the present embodiment is preferably used.

Hereinafter, an example of the image forming apparatus according to the present embodiment is shown, but the present invention is not limited thereto. In the following description, main portions shown in the drawings are described, and descriptions of other portions are omitted.

Fig. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.

The image forming apparatus shown in fig. 1 includes 1 st to 4 th image forming units 10Y, 10M of an electrophotographic system for printing yellow (Y), magenta (M), cyan (C), black (K) images based on color-separated image data,

10C, 10K (image forming members). These image forming units (hereinafter, may be simply referred to as "units") 10Y, 10M,

10C, 10K are juxtaposed in a horizontal direction at a predetermined distance from each other. These units 10Y, 10M,

10C and 10K may be process cartridges attached to and detached from the image forming apparatus.

Above each unit 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 is provided so as to extend through each unit. The intermediate transfer belt 20 is provided to be wound around a driving roller 22 and a supporting roller 24, and travels in a direction from the 1 st unit 10Y toward the 4 th unit 10K. The backup roller 24 is biased in a direction away from the drive roller 22 by a spring or the like, not shown, to apply tension to the intermediate transfer belt 20 wound around both. An intermediate transfer body cleaning device 30 is provided on the image holding surface side of the intermediate transfer belt 20 so as to face the driving roller 22.

The toners of yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K are supplied to developing devices (an example of a developing member) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K, respectively.

Since the 1 st to 4 th units 10Y, 10M, 10C, and 10K have the same structure and operation, the 1 st unit 10Y, which forms a yellow image, disposed on the upstream side in the traveling direction of the intermediate transfer belt will be described as a representative.

The 1 st unit 10Y has a photoconductor 1Y functioning as an image holder. Around the photoconductor 1Y, there are sequentially arranged: a charging roller (an example of a charging member) 2Y for charging the surface of the photoconductor 1Y with electricity of a predetermined potential; an exposure device (an example of an electrostatic latent image forming means) 3 for forming an electrostatic latent image by exposing the charged surface with a laser beam 3Y based on the color-separated image signal; a developing device (an example of a developing member) 4Y for supplying charged toner to the electrostatic latent image to develop the electrostatic latent image; a primary transfer roller (an example of a primary transfer member) 5Y for transferring the developed toner image onto the intermediate transfer belt 20; and a photoconductor cleaning device (an example of a cleaning member) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer.

The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20 and is disposed at a position facing the photoconductor 1Y. Bias power supplies (not shown) for applying primary transfer biases are connected to the primary transfer rollers 5Y, 5M, 5C, and 5K of each unit. The bias power supplies change the value of the transfer bias applied to the primary transfer rollers under the control of a control unit, not shown.

Hereinafter, an operation of forming a yellow image in the 1 st unit 10Y will be described.

First, before the operation, the surface of the photoreceptor 1Y is charged with electricity of a potential of-600V to-800V by the charging roller 2Y.

The photoreceptor 1Y is formed by a conductive material (for example, a material having a volume resistivity of 1X 10 at 20 DEG C ^-6 Omega cm or less) is formed by laminating a photosensitive layer on a substrate. In general, the photosensitive layer has a high resistance (resistance of a general resin), but has a property that the resistivity of a portion to which a laser beam is irradiated changes when the laser beam is irradiated. Therefore, the laser beam 3Y is irradiated from the exposure device 3 onto the surface of the charged photoconductor 1Y based on the yellow image data transmitted from the control unit, not shown. Thereby, an electrostatic latent image of a yellow image pattern is formed on the surface of the photoconductor 1Y.

The electrostatic latent image is an image formed on the surface of the photoconductor 1Y by charging, and is a so-called negative latent image, which is formed as follows: the electric charge charged on the surface of the photoreceptor 1Y is caused to flow by lowering the resistivity of the irradiated portion of the photosensitive layer by the laser beam 3Y, while the electric charge remains in the portion where the laser beam 3Y is not irradiated.

The electrostatic latent image formed on the photoconductor 1Y rotates to a preset development position as the photoconductor 1Y advances. Then, at this development position, the electrostatic latent image on the photoconductor 1Y is developed into a toner image by the developing device 4Y, and visualized.

The developing device 4Y accommodates therein, for example, an electrostatic latent image developer containing at least yellow toner and a carrier. The yellow toner is triboelectrically charged by stirring in the developing device 4Y, and is held by a developer roller (an example of a developer holder) with a charge of the same polarity (negative polarity) as that of the charge of the photoconductor 1Y. By passing the surface of the photoconductor 1Y through the developing device 4Y, the yellow toner electrostatically adheres to the charge-removed latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. The photoreceptor 1Y on which the yellow toner image is formed continues to travel at a predetermined speed, so that the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is transferred to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roller 5Y acts on the toner image to transfer the toner image on the photoconductor 1Y to the intermediate transfer belt 20. The transfer bias applied at this time is (+) in polarity opposite to the polarity (-) of the toner, and is controlled to +10μa by a control unit (not shown) in the 1 st unit 10Y.

The toner remaining on the photoconductor 1Y is removed and collected by the photoconductor cleaning device 6Y.

The primary transfer bias applied to the primary transfer rollers 5M, 5C, 5K after the 2 nd unit 10M is also controlled with reference to the 1 st unit.

In this way, the intermediate transfer belt 20 after the yellow toner image is transferred by the 1 st unit 10Y is sequentially conveyed so as to pass through the 2 nd to 4 th units 10M, 10C, 10K, and is transferred a plurality of times so as to superimpose the toner images of the respective colors.

The intermediate transfer belt 20 after the toner images of four colors are transferred a plurality of times through the 1 st to 4 th units reaches a secondary transfer portion composed of the intermediate transfer belt 20, a backup roller 24 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer member) 26 that is disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, at a predetermined timing, a recording sheet (an example of a recording medium) P is fed to a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are in contact via a feeding mechanism, and a secondary transfer bias is applied to the backup roller 24. The transfer bias applied at this time is of the same polarity (-) as the polarity (-) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image to transfer the toner image on the intermediate transfer belt 20 to the recording paper P. The secondary transfer bias at this time is determined based on the resistance detected by a resistance detecting member (not shown) that detects the resistance of the secondary transfer portion, and is voltage-controlled.

Then, the recording sheet P is conveyed to a nip portion (nip portion) of a pair of fixing rollers of a fixing device (an example of a fixing member) 28, and the toner image is fixed to the recording sheet P to form a fixed image.

The recording paper P on which the toner image is transferred includes, for example, plain paper used in electrophotographic copying machines, printers, and the like. The recording medium includes an OHP sheet, in addition to the recording paper P.

In order to further improve the smoothness of the image surface after fixing, for example, the surface of the recording paper P is preferably also smooth, and for example, coated paper obtained by coating the surface of plain paper with a resin or the like, coated paper for printing, or the like is preferably used.

The recording paper P after fixing the color image is conveyed to the discharge portion, and a series of color image forming operations is terminated.

< Process Cartridge, toner Cartridge >)

A process cartridge according to the present embodiment will be described.

The process cartridge according to the present embodiment includes a developing member that accommodates the electrostatic latent image developer according to the present embodiment and develops an electrostatic latent image formed on a surface of an image holding member into a toner image with the electrostatic latent image developer, and is attached to and detached from an image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above-described configuration, and may be configured to include a developing member and at least one member selected from other members provided as needed, for example, an image holding body, a charging member, an electrostatic latent image forming member, a transfer member, and the like.

Hereinafter, an example of the process cartridge according to the present embodiment is shown, but the present invention is not limited thereto. In the following description, main portions shown in the drawings are described, and descriptions of other portions are omitted.

Fig. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.

The process cartridge 200 shown in fig. 2 is configured to be a cartridge in which, for example, a photoconductor 107 (an example of an image holder), a charging roller 108 (an example of a charging member) provided around the photoconductor 107, a developing device 111 (an example of a developing member), and a photoconductor cleaning device 113 (an example of a cleaning member) are integrally held by a frame 117 provided with a mounting rail 116 and an opening 118 for exposure.

In fig. 2, 109 denotes an exposure device (an example of an electrostatic latent image forming member), 112 denotes a transfer device (an example of a transfer member), 115 denotes a fixing device (an example of a fixing member), and 300 denotes a recording sheet (an example of a recording medium).

Next, a toner cartridge according to the present embodiment will be described.

The toner cartridge according to the present embodiment is a toner cartridge that accommodates the toner according to the present embodiment and is attached to and detached from an image forming apparatus. The toner cartridge accommodates a replenishment toner for supplying to a developing member provided in the image forming apparatus.

The image forming apparatus shown in fig. 1 is an image forming apparatus having a structure in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and developing devices 4Y, 4M, 4C, and 4K are connected to toner cartridges corresponding to respective developing devices (colors) through toner supply pipes, not shown. When the toner contained in the toner cartridge is reduced, the toner cartridge is replaced.

Examples

Embodiments of the present invention will be described in detail below with reference to examples, but embodiments of the present invention are not limited to these examples.

In the following description, unless otherwise specified, "parts" and "%" are based on mass.

Unless otherwise indicated, synthesis, handling, production, etc. are carried out at room temperature (25 ℃.+ -. 3 ℃).

Preparation of particle Dispersion

[ preparation of amorphous resin particle Dispersion (1-1) ]

The above material was charged into a reaction vessel equipped with a stirring device, a nitrogen inlet, a temperature sensor and a rectifying column, the temperature was raised to 190℃over 1 hour, and 1.2 parts of dibutyltin oxide was added to 100 parts of the above material. The resultant water was distilled off, and the temperature was raised to 240℃over 6 hours, and the reaction mixture was kept at 240℃for 3 hours, followed by dehydration condensation reaction, and then cooled.

The reaction mixture was transferred to Cavitron CD1010 (manufactured by EUROTEC Co.) in a molten state at a rate of 100 g/min. Simultaneously, ammonia water having a concentration of 0.37% prepared separately was heated to 120℃by a heat exchanger, and transferred to Cavitro CD1010 at a rate of 0.1 liter per minute. At a rotational speed of the rotor of 60Hz and a pressure of 5kg/cm ² Cavitro CD1010 was run under the conditions of (2) to obtain a resin particle dispersion in which resin particles of an amorphous polyester resin having a volume average particle diameter of 169nm were dispersed. Deionized water was added to the resin particle dispersion to adjust the solid content to 20%, thereby obtaining an amorphous resin particleResin particle dispersion (1-1). The SP value (R) of the amorphous polyester resin was 9.41.

[ preparation of amorphous resin particle Dispersion (1-2) ]

A mixture obtained by mixing and dissolving the above materials was dispersed in a surfactant solution obtained by dissolving 1.2 parts of an anionic surfactant (TaycaPower, TAYCA co., ltd.) in 100 parts of deionized water in a flask, and emulsified. Next, an aqueous solution obtained by dissolving 6 parts of ammonium persulfate in 50 parts of deionized water was poured over 20 minutes while stirring the flask. Next, after nitrogen substitution, the contents were heated to 75 ℃ in an oil bath while stirring the flask, and maintained at 75 ℃ for 4 hours, and emulsion polymerization was continued. Thus, a resin particle dispersion in which resin particles of an amorphous styrene acrylic resin having a volume average particle diameter of 160nm and a weight average molecular weight of 56000 were dispersed was obtained. Deionized water was added to the resin particle dispersion to adjust the solid content to 31.4% to obtain an amorphous resin particle dispersion (1-2). The SP value (R) of the amorphous styrene acrylic resin was 9.14.

[ preparation of amorphous resin particle Dispersion (1-3) ]

The reaction mixture was transferred to Cavitron CD1010 (manufactured by EUROTEC Co.) in a molten state at a rate of 100 g/min. At the same timeSeparately prepared 0.37% strength ammonia was transferred to the Cavitron CD1010 at a rate of 0.1 liter per minute while heating the ammonia water to 120 ℃ with a heat exchanger. At a rotational speed of the rotor of 60Hz and a pressure of 5kg/cm ² Cavitro CD1010 was run under the conditions of (2) to obtain a resin particle dispersion in which resin particles of an amorphous polyester resin having a volume average particle diameter of 175nm were dispersed. Deionized water was added to the resin particle dispersion to adjust the solid content to 20% to obtain an amorphous resin particle dispersion (1-3). The SP value (R) of the amorphous polyester resin was 9.43.

[ preparation of crystalline resin particle Dispersion (1-4) ]

1, 10-dodecanedioic acid: 225 parts

1, 6-hexanediol: 143 parts of

The above materials were charged into a reaction vessel equipped with a stirring device, a nitrogen inlet, a temperature sensor and a rectifying column, and the temperature was raised to 160℃over 1 hour, and 0.8 parts of dibutyltin oxide was charged. The resulting water was distilled off, and the temperature was raised to 180℃over 6 hours, and the dehydration condensation reaction was continued for 5 hours while maintaining 180 ℃. Then, the temperature was gradually raised to 230℃under reduced pressure, and 230℃was maintained, followed by stirring for 2 hours. Then, the reaction product was cooled, solid-liquid separation was performed, and the solid was dried to obtain a crystalline polyester resin.

The materials were charged into a jacketed reaction vessel equipped with a condenser, a thermometer, a water dropping device and an anchor wing, and the resin was dissolved while stirring and mixing the materials at 100rpm while maintaining the liquid temperature at 80℃in a water circulation type thermostatic bath. Next, the water circulation type constant temperature bath was set to 50 ℃, and 400 parts of deionized water held at 50 ℃ was added dropwise in total at a rate of 7 parts/min to obtain an emulsion. 576 parts of emulsion and 500 parts of deionized water were placed in an eggplant-shaped flask, and they were set in an evaporator equipped with a vacuum control unit via a trap ball. While the eggplant-shaped flask was rotated, the flask was warmed by a hot water bath at 60℃and the pressure was reduced to 7kPa while taking care of boiling, thereby removing the solvent. The volume average particle diameter of the resin particles in the dispersion was 185nm. Deionized water was added to obtain a crystalline resin particle dispersion (1-4) having a solid content of 22.1%.

[ preparation of resin particle Dispersion (2-1) ]

The above materials were put into a flask to be mixed and dissolved, and 60 parts of deionized water was further added to be dispersed, thereby preparing an emulsion. 1.3 parts of an anionic surfactant (manufactured by The Dow Chemical Company, dowfax2 A1) was dissolved in 90 parts of deionized water, 1 part of an emulsion was added thereto, and a solution obtained by dissolving 5.4 parts of ammonium persulfate in 10 parts of deionized water was further added thereto. Then, the remaining emulsion was added over 180 minutes. Next, nitrogen substitution in the flask was performed, and the solution in the flask was stirred and heated to 65 ℃ in an oil bath. The emulsion polymerization was carried out by keeping the liquid temperature at 65℃and stirring for 500 minutes. Next, the solid content was adjusted to 24.5% by deionized water to obtain a resin particle dispersion (2-1).

[ preparation of resin particle Dispersion (2-2) to (2-14), (2-C1) and (2-C2) ]

Resin particle dispersions (2-2) to (2-14), (2-C1) and (2-C2) were prepared in the same manner as in the preparation of the resin particle dispersion (2-1), except that the amounts of the monomers, the types and amounts of the crosslinking agents, the total amount of the surfactants, the amount of ammonium persulfate, the temperature heated in the oil bath (the "polymerization temperature" in the table), the time taken for charging the remaining emulsion (the "addition time" in the table) and the duration of the emulsion polymerization (the "holding time" in the table) were changed as described in table 1.

TABLE 1

Physical properties of the crosslinked resin particles contained in the resin particle dispersion (2-1) and the like are shown in Table 2. Abbreviations in table 2 represent the following meanings.

Tg: glass transition temperature

G'90-150 (small): minimum value of storage elastic modulus G' (p 90-150) in the range of 90 ℃ to 150 DEG C

G'90-150 (large): maximum value of storage elastic modulus G' (p 90-150) in the range of 90 ℃ to 150 DEG C

tan delta 30-150 (small): minimum value of loss tangent tan delta in the range of 30 ℃ to 150 DEG C

tan delta 30-150 (large): a maximum value of loss tangent tan delta in a range of 30 ℃ to 150 DEG C

tan delta 65-150 (small): minimum value of loss tangent tan delta in the range of 65 ℃ to 150 DEG C

tan delta 65-150 (large): maximum value of loss tangent tan delta in the range of 65 ℃ to 150 DEG C

TABLE 2

[ preparation of colorant particle Dispersion (1) ]

Cyan Pigment (Pigment Blue) 15:3, dainichiseika Color & Chemicals mfg.co., ltd.): 98 parts of

Anionic surfactant (TaycaPower, TAYCA co., ltd.): 2 parts of

Deionized water: 420 parts

The above materials were mixed and subjected to a dispersion treatment for 10 minutes by a homogenizer (IKA ULTRA TURRAX) to obtain a colorant particle dispersion (1) having a volume average particle diameter of 164nm and a solid content of 21.1%.

[ preparation of Release agent particle Dispersion (1) ]

Synthetic wax (FNP 92, NIPPON SEIRO co., ltd.): 50 parts of

Anionic surfactant (TaycaPower, TAYCA co., ltd.): 1 part of

Deionized water: 200 parts of

The above materials were mixed and heated to 130℃and then subjected to dispersion treatment by a homogenizer (ULTRA TURRAX T50, IKA Co.) and then subjected to dispersion treatment by a pressure discharge homogenizer. When the volume average particle diameter was 200nm, the mixture was recovered to obtain a release agent particle dispersion (1) having a solid content of 20%.

< manufacturing of toner particles >

[ production of toner particles (1) ]

The above material having a liquid temperature adjusted to 10℃was placed in a cylindrical stainless steel vessel, and the material was dispersed and mixed for 2 minutes while applying a shearing force at 4000rpm by a homogenizer (ULTRA TURRAX T50, manufactured by IKA Co.). Next, 1.75 parts of a 10% aqueous nitric acid solution of aluminum sulfate was gradually added dropwise as a coagulant, and the rotation speed of the homogenizer was raised to 10000rpm to perform a dispersion treatment for 10 minutes, thereby obtaining a raw material dispersion.

The raw material dispersion was transferred to a stirring apparatus having two paddle stirring blades and a reaction vessel having a thermometer. While stirring at 550rpm, heating was started by a covered heater, the temperature of the solution was raised to 40 ℃, the pH of the raw material dispersion was controlled to be in the range of 2.2 to 3.5 by using 0.3M nitric acid and 1M sodium hydroxide aqueous solution, and the temperature and pH were maintained for about 2 hours to grow agglomerated particles. Then, a dispersion liquid obtained by mixing 21 parts of the amorphous resin particle dispersion liquid (1-1) and 8 parts of the resin particle dispersion liquid (2-1) was added and kept for 60 minutes, whereby amorphous resin particles and crosslinked resin particles were adhered to the surfaces of the aggregated particles. Then, the liquid temperature was raised to 53℃and 21 parts of the amorphous resin particle dispersion (1-1) was added thereto, followed by holding for 60 minutes, whereby amorphous resin particles were further adhered to the surfaces of the aggregated particles.

The agglomerated particles were aligned while confirming the size and shape of the particles by an optical microscope and a particle diameter measuring device. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution, and the mixture was kept for 15 minutes. Next, after the pH was raised to 8.0 using 5% aqueous sodium hydroxide, the liquid temperature was raised to 85 ℃. Melting of the agglomerated particles was confirmed by an optical microscope, and after 2 hours, heating was stopped and cooling was performed at a rate of 1.0 ℃/min. Solid-liquid separation was performed with a 20 μm sieve, and after repeated washing with water, drying was performed with a vacuum dryer to obtain toner particles (1). The volume average particle diameter of the toner particles (1) was 5.3. Mu.m.

[ production of toner particles (2) to (15), (17), (18), (23) to (32), (C1) and (C2) ]

Each toner particle was produced in the same manner as in the production of toner particle (1), except that the amounts of addition of each resin particle dispersion were adjusted to the crystalline resin and the content of resin particles was as shown in tables 3-1 to 3-4 using the types of resin particle dispersions described in tables 3-1 to 3-4.

[ production of toner particles (16) ]

Toner particles (16) were produced in the same manner as in the production of toner particles (1), except that the rotational speed of the homogenizer at the time of preparing the raw material dispersion was changed from 10000rpm to 5000 rpm.

[ production of toner particles (19) ]

Toner particles (19) were produced in the same manner as in the production of toner particles (1), except that the pH at which the aggregated particles were melted was changed from 8.0 to 9.0.

[ production of toner particles (20) ]

Toner particles (20) were produced in the same manner as in the production of toner particles (1), except that the pH at which the aggregated particles were melted was changed from 8.0 to 5.5.

[ production of toner particles (21) ]

Toner particles (21) were produced in the same manner as in the production of toner particles (1), except that the addition amount of each resin particle dispersion was adjusted so that the crystalline resin and the resin particle content became the contents shown in tables 3 to 3, and the pH at the time of melting the aggregated particles was changed from 8.0 to 9.5.

[ production of toner particles (22) ]

Toner particles (22) were produced in the same manner as in the production of toner particles (1), except that the addition amount of each resin particle dispersion was adjusted so that the crystalline resin and the resin particle content became the contents shown in tables 3 to 3, and the pH at which the aggregated particles were melted was changed from 8.0 to 6.0.

[ production of toner particles (C3) ]

The above materials having the liquid temperature adjusted to 30℃were placed in a cylindrical stainless steel vessel, and subjected to a dispersion treatment for 2 minutes while shearing force was applied at 4000rpm by a homogenizer (ULTRA TURRAX T50, manufactured by IKA Co.), and mixed. Next, 1.75 parts of a 10% aqueous nitric acid solution of aluminum sulfate was gradually added dropwise as a coagulant, and dispersion treatment was performed at 4000rpm of the homogenizer for 3 minutes to obtain a raw material dispersion.

The agglomerated particles were aligned while confirming the size and shape of the particles by an optical microscope and a particle diameter measuring device. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution, and the mixture was kept for 15 minutes. Next, after the pH was raised to 8.0 using 5% aqueous sodium hydroxide, the liquid temperature was raised to 85 ℃. Melting of the agglomerated particles was confirmed by an optical microscope, and after 2 hours, heating was stopped and cooling was performed at a rate of 1.0 ℃/min. After solid-liquid separation with a 20 μm sieve and repeated washing with water, the resultant was dried with a vacuum dryer to obtain toner particles (C3).

[ production of toner particles (C4) ]

The raw material dispersion was transferred to a stirring apparatus having two paddle stirring blades and a reaction vessel having a thermometer. While stirring at 550rpm, heating was started by a covered heater, the temperature of the solution was raised to 40 ℃, the pH of the raw material dispersion was controlled to be in the range of 2.2 to 3.5 by using 0.3M nitric acid and 1M sodium hydroxide aqueous solution, and the temperature and pH were maintained for about 2 hours to grow agglomerated particles. Then, 42 parts of the amorphous resin particle dispersion (1-1) was added and the mixture was kept for 60 minutes, whereby amorphous resin particles were adhered to the surfaces of the aggregated particles.

The agglomerated particles were aligned while confirming the size and shape of the particles by an optical microscope and a particle diameter measuring device. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution, and the mixture was kept for 15 minutes. Next, after the pH was raised to 8.0 using 5% aqueous sodium hydroxide, the liquid temperature was raised to 85 ℃. Melting of the agglomerated particles was confirmed by an optical microscope, and after 2 hours, heating was stopped and cooling was performed at a rate of 1.0 ℃/min. After solid-liquid separation with a 20 μm sieve and repeated washing with water, the resultant was dried with a vacuum dryer to obtain toner particles (C4).

[ production of toner particles (C5) ]

The raw material dispersion was transferred to a stirring apparatus having two paddle stirring blades and a reaction vessel having a thermometer. While stirring at 550rpm, heating was started by a covered heater, the temperature of the solution was raised to 40 ℃, the pH of the raw material dispersion was controlled to be in the range of 2.2 to 3.5 by using 0.3M nitric acid and 1M sodium hydroxide aqueous solution, and the temperature and pH were maintained for about 2 hours to grow agglomerated particles. Next, the dispersion liquid obtained by mixing 42 parts of the amorphous resin particle dispersion liquid (1-1) and 41 parts of the resin particle dispersion liquid (2-1) was divided into two, and added 2 times, and the mixture was kept for 60 minutes, whereby amorphous resin particles and crosslinked resin particles were adhered to the surfaces of the aggregated particles.

The agglomerated particles were aligned while confirming the size and shape of the particles by an optical microscope and a particle diameter measuring device. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution, and the mixture was kept for 15 minutes. Next, after the pH was raised to 8.0 using 5% aqueous sodium hydroxide, the liquid temperature was raised to 85 ℃. Melting of the agglomerated particles was confirmed by an optical microscope, and after 2 hours, heating was stopped and cooling was performed at a rate of 1.0 ℃/min. After solid-liquid separation with a 20 μm sieve and repeated washing with water, the resultant was dried with a vacuum dryer to obtain toner particles (C5).

[ production of toner particles (C6) ]

Toner particles (C6) were produced in the same manner as in the production of toner particles (1), except that resin particle dispersion (2-1) was not used.

[ production of toner particles (C7) ]

Toner particles (C7) were produced in the same manner as in the production of toner particles (1), except that the pH at the time of melting the aggregated particles was changed from 8.0 to 6.5, the liquid temperature at the time of melting the aggregated particles was changed from 85 ℃ to 75 ℃, and 5.2 parts of anionic surfactant (manufactured by The Dow Chemical Company, dowfax2 A1) was added immediately after the temperature was reached.

[ production of toner particles (C8) ]

Toner particles (C8) were produced in the same manner as in the production of toner particles (1), except that the pH at the time of melting the aggregated particles was changed from 8.0 to 10.0 and the liquid temperature at the time of melting the aggregated particles was changed from 85 ℃ to 95 ℃.

Tables 3-1 to 3-4 show types of dispersions used in the production of toner particles, average particle diameters Dp of resin particles in toner particles, proportions of crystalline resin in binder resin, volume average particle diameters of toner particles, and the like.

Abbreviations in tables 3-1 to 3-4 have the following meanings.

Crystalline resin/resin particles: content of crystalline resin relative to content of resin particles, quality standard

Amorphous resin/resin particles: content of amorphous resin relative to content of resin particles, quality standard

THF soluble component Mn: number average molecular weight of tetrahydrofuran soluble fraction of toner particles

SP value difference: SP value (S) -SP value (R)

30-50G': storage elastic modulus G 'in a range of 30 ℃ to 50 ℃ inclusive of other components than toner particles'

The temperature is reached: the toner particles have an excluded component of less than 1×10 ⁵ Temperature at which the storage modulus G' of Pa

tan delta: loss tangent tan delta at the above-mentioned reached temperature

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Production of silica particles (A)

[ preparation of base catalyst solution ]

The amount and concentration of methanol and aqueous ammonia shown in Table 4 were put into a glass reaction vessel equipped with a metal stirring rod, a dropping nozzle and a thermometer, and stirred and mixed to obtain a base catalyst solution.

[ granulating silica masterbatch by Sol-gel method ]

The temperature of the base catalyst solution was adjusted to 40 ℃, and nitrogen substitution was performed on the base catalyst solution. While stirring the base catalyst solution at 40℃under stirring, tetramethoxysilane (TMOS) and catalyst (NH) were added dropwise in the amounts shown in Table 4 ₃ ) 124 parts of ammonia water with the concentration of 7.9% is used for obtaining a silica master batch suspension.

[ addition of silane coupling agent ]

While stirring the silica master batch suspension at a liquid temperature of 40 ℃, methyltrimethoxysilane (MTMS) was added in an amount shown in table 4. After the addition, stirring was continued for 120 minutes to allow the MTMS to react, and at least a part of the surface of the silica master batch was coated with the reaction product of the MTMS.

[ addition of molybdenum-containing Nitrogen Compound ]

An alcohol solution was prepared by diluting the molybdenum-nitrogen-containing compound in the amount shown in table 4 with butanol. The alcohol solution was added to the silica master batch suspension after the reaction of the silane coupling agent, and the solution was stirred for 100 minutes while maintaining the liquid temperature at 30 ℃. The amount of the alcohol solution to be added was such that the amount of the molybdenum-nitrogen-containing compound per 100 parts by mass of the solid content of the silica master batch suspension was as shown in Table 4.

"TP-415" in Table 4 is a quaternary ammonium molybdate (HODOGAYA CHEMICAL CO., LTD.).

[ drying ]

The suspension after the addition of the molybdenum-nitrogen-containing compound was transferred to a reaction tank for drying. While stirring the suspension, liquefied carbon dioxide was injected into the reaction tank, the temperature in the reaction tank was raised to 150℃and 15MPa, and the suspension was continuously stirred while maintaining the supercritical state of carbon dioxide at a constant temperature and pressure. Carbon dioxide was introduced into and discharged from the reactor at a flow rate of 5L/min, and the solvent was removed over 120 minutes to obtain silica particles (A). Silica particles (A1) to (A13) were produced by adjusting the amounts of ammonia, silane coupling agent and molybdenum-nitrogen-containing compound to be added.

[ fluorescent X-ray analysis ]

The fluorescent X-ray analysis of the silica particles (A) was performed according to the above-described measurement method to obtain the Net intensity N of molybdenum element _Mo Net strength N of silicon element _Si The Net intensity ratio N is calculated _Mo /N _Si 。

The average primary particle diameters and Net strength ratios of the silica particles (A1) to (a 13) are shown in table 4.

TABLE 4

Production of silica particles (B)

[ production of silica particles (B1) ]

Silica particles having average primary particle diameters of 80nm, 120nm and 150nm were produced by a known sol-gel method. The surface treatment with HMDS (1, 3-hexamethyldisilazane) gave three silica particles (B1) having different average primary particle diameters.

[ production of silica particles (B2) ]

Silica particles having an average primary particle diameter of 55nm were produced by a known sol-gel method. 100 parts of silica particles and 500 parts of toluene were placed in an evaporator, and the temperature was maintained at 40℃and stirred for 15 minutes. Next, 10 parts of simethicone was placed in 100 parts of silica particles and stirred for 15 minutes, and then 20 parts of simethicone was added thereto and stirred for 15 minutes. The temperature was raised to 90℃and the toluene was dried under reduced pressure. Then, the treated product was taken out and vacuum-dried at 120℃for 30 minutes to obtain silica particles (B2).

Production of strontium titanate particles

[ strontium titanate particles (1) ]

Collect TiO ₂ 0.7 mole of meta-titanic acid as a desulphurised and peptized titanium source was placed in the reaction vessel. Next, 0.77 mol of strontium chloride aqueous solution was added to the reaction vessel to give SrO/TiO ₂ The molar ratio was 1.1. Initial TiO in a mixed solution of two materials ₂ The concentration was set at 0.75 mol/L. Subsequently, the mixed solution was stirred, the mixed solution was heated to 120 ℃, and 153mL of 10N aqueous sodium hydroxide solution was added over 4.2 hours while the liquid temperature was maintained at 120 ℃ and stirring was continued for 1 hour while the liquid temperature was maintained at 120 ℃. Subsequently, the reaction solution was cooled to 40 ℃, and hydrochloric acid was added thereto and stirred for 1 hour until the pH became 5.5. Next, the precipitate was washed by repeating decantation and redispersion in water. Hydrochloric acid was added to the slurry containing the washed precipitate, the pH was adjusted to 6.5, and the solid content was filtered off and dried to obtain strontium titanate particles (1).

[ strontium titanate particles (2) to (10) ]

Strontium titanate particles (2) to (10) were produced in the same manner as in the production of strontium titanate particles (1), except that the time taken for dropping the 10N aqueous sodium hydroxide solution was changed to the time described in table 5.

[ strontium titanate particles (11) to (15) ]

1L of a 2.5M aqueous oxalic acid solution was placed in a reaction vessel. Further, 1 mol of barium chloride and 2 mol of titanium tetrachloride were collected and diluted with 1L of water to prepare a mixed solution. While stirring the oxalic acid aqueous solution, the mixture was added while heating to 70 ℃. After removing the supernatant, decantation using 5L of water was repeated 2 times. A cake layer was formed on the suction filter by suction filtration, and 5L of water was passed through the cake layer for washing. Taking out the cleaned filter cake layer as a solid substance, and drying at 110 ℃ for 8 hours to obtain a strontium titanate dried product. The strontium titanate dried product was placed in an alumina crucible and calcined at 930 ℃. After the calcination treatment, the strontium titanate particles (11) to (15) are obtained by pulverizing and classifying the particles by a mechanical pulverizing device.

[ measurement of particle size of strontium titanate particles ]

Toner particles and strontium titanate particles (1) to (15) were mixed at a stirring peripheral speed of 30 m/sec for 15 minutes using a henschel mixer. Then, the resultant was sieved using a vibrating screen having a pore diameter of 45 μm to obtain an externally added toner having strontium titanate particles attached thereto.

The average primary particle diameter of strontium titanate particles was measured by the above-described measurement method using the externally added toner as a sample.

TABLE 5

< preparation of fatty acid Metal salt particles >

Commercially available zinc stearate was pulverized and classified by a jet mill to prepare an average primary particle size as shown in Table 6-1.

< manufacturing of Carrier >)

The above material and glass beads (diameter: 1mm, same amount as toluene) were put into a sand mill and stirred at 190rpm for 30 minutes to obtain a coating agent.

1000 parts of ferrite particles (volume average particle diameter 35 μm) and 150 parts of a coating agent were charged into a kneader, and mixed at room temperature (25 ℃) for 20 minutes. Then, the mixture was heated to 70℃and reduced in pressure to dry the mixture. The dried product was cooled to room temperature (25 ℃ C.), and the dried product was taken out from the kneader, sieved with a sieve having a pore size of 75 μm, and coarse powder was removed to obtain a carrier.

Toner and production of two-component developer

Examples 1 to 47 and comparative examples 1 to 2

100 parts of toner particles (1), zinc stearate particles, any of silica particles (A1) to (a 13), any of strontium titanate particles (1) to (15), any of three kinds of silica particles (B1) having different average primary particle diameters, and silica particles (B2) were mixed in an amount shown in table 6-1 or the like by a henschel mixer, and sieved with a vibrating screen having a pore diameter of 45 μm to obtain a toner. 8 parts of toner and 100 parts of carrier were put into a V mixer and stirred, and sieved with a sieve having a pore diameter of 212. Mu.m, to obtain a two-component developer.

Examples 48 to 85 and comparative example 3

Toner and two-component developer were produced in the same manner as in example 10 except that 100 parts of toner particles (1) were changed to 100 parts of any one of toner particles (2) to (32) and (C1) to (C8).

< evaluation of Performance >

[ color stripe (1) ]

The developer of the image forming apparatus (FUJIFILM Business Innovation Japan Corp. DocuCentreColor a) was filled with the two-component developer, and a test image having a cyan image density of 5% was continuously copied on 1 ten thousand A4 plain papers under a high-temperature and high-humidity environment (temperature 28 ℃ C. And relative humidity 85%). Then, the image forming apparatus was immediately moved to a low-temperature and low-humidity environment (temperature 10 ℃ and relative humidity 15%), and a copy of a test image having an image density of 5% of cyan was continuously performed on 2 ten thousand A4 plain papers. The last 1 sheets were observed with the naked eye, and the surface of the photoreceptor was observed with a microscope, and the generation of color streaks was classified as follows. The results are shown in Table 6-1 and Table 7-1.

G1: there is no color streak on the paper. There is no color stripe on the photoreceptor.

And G2: there is no color streak on the paper. There is very slight color streak on the photoreceptor.

And G3: there is no color streak on the paper. There are slight color stripes on the photoreceptor.

And G4: color stripes are present on the paper surface. Color stripes are present on the entire surface of the photoreceptor.

[ color stripe (2) ]

The developing device of the image forming apparatus (FUJIFILM Business Innovation Japan Corp. Manufactured by DocuCentreColor a) was filled with the two-component developer, and a test image having a cyan image density of 1% was copied on 1 ten thousand A4 plain papers under a high-temperature and high-humidity environment (temperature 28 ℃ C. And relative humidity 85%). The test image was printed 1 sheet every 15 seconds. The last 1 sheets were observed with the naked eye, and the surface of the photoreceptor was observed with a microscope, and the generation of color streaks was classified as follows. The results are shown in Table 6-1, etc.

[ concentration Difference of image ]

The developer of the image forming apparatus (FUJIFILM Business Innovation Japan Corp. Manufactured by DocuCentreColor a) was filled with the two-component developer, and the cyan test image was continuously copied on 3 ten thousand sheets of A4 plain paper under a high-temperature and high-humidity environment (temperature 28 ℃ C. And relative humidity 85%). The test image is an image in which an A4 sheet is divided into four equal parts in the longitudinal direction and image portions and non-image portions having an image density of 100% are alternately arranged. After 3 ten thousand test images were copied, 100 images having a density of 100% of the entire area image were copied, and the last 1 image was visually observed, and the density differences of the images were classified as follows. The results are shown in Table 6-1, etc.

G1: no shade was observed by naked eyes, and no concentration difference was observed when measured by a concentration meter.

And G2: no shade was observed by the naked eye, but there was a slight difference in concentration when measured with a concentration meter.

And G3: no shade was observed by the naked eye, but there was a difference in concentration when measured by a concentration meter.

And G4: the shade was visually separated, and a concentration difference was found when measured by a concentration meter.

[ gloss poor ]

The developers of the examples and comparative examples were filled in a developer of an image forming apparatus apeosoportiv C3370 (manufactured by FUJIFILM Business Innovation Japan corp.) from which the fixing device was taken out.

A fixing device is prepared which is modified to be taken out of an image forming apparatus and in which fixing temperature and holding pressure can be arbitrarily changed.

OS coated W paper of A4 size (basis weight 127g/m ² FUJIFILM Business Innovation Japan Corp.) to a toner bearing capacity of 0.45mg/cm ² 50mm x 50mm unfixed image of (a).

Using a fixing device at a process speed of 175mm/sec under low temperature and low pressure conditions (fixing device temperature 120 ℃ C., nip pressure 1.6 kgf/cm) ² ) And high temperature and high pressure conditions (fixing device temperature 180 ℃ C., nip pressure 6.0 kgf/cm) ² ) The unfixed image is fixed under both conditions, resulting in a fixed image.

The glossiness of the fixed image was measured at a measurement angle of 60 ° using a gloss meter (micro-tri-gloss, manufactured by BYK corporation). The difference in glossiness between the fixed image under low temperature and low pressure conditions and the fixed image under high temperature and high pressure conditions was obtained. The results are shown in tables 7-1 to 7-4.

[ fixing Property ]

The fixed image under low temperature and low pressure conditions in the evaluation of the difference in gloss was folded, and a weight was placed on the folded fixed image. The image of the unfolded and folded portion was visually observed, and the image defects were classified as follows. The results are shown in tables 7-1 to 7-4.

G1: no image defects were observed.

And G2: image defects were observed, but slight.

And G3: slight image defects were observed, but were within the allowable range.

And G4: image defects were observed.

The "amount added" shown in tables 6-1 to 6-3 is a mass part per 100 mass parts of toner particles.

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Abbreviations in tables 7-1 to 7-4 have the following meanings.

Difference (150): d50 (150) -D1 (150) value of toner

Difference (90): d50 (90) -D1 (90) value of toner

30-50G': storage elastic modulus G 'of toner in the range of 30 ℃ to 50℃'

The temperature is reached: the toner reaches less than 1×10 ⁵ Temperature at which the storage modulus G' of Pa

Difference in visco-elastic properties: values of logG '(t 90-150) -logG' (r 90-150)

(1)

A toner for developing an electrostatic latent image, comprising:

toner particles containing a binder resin and resin particles;

fatty acid metal salt particles externally added to the toner particles; and

(2)

The toner for developing an electrostatic latent image according to (1), wherein,

the ratio N of the silica particles (A) _Mo /N _Si Is 0.05 to 0.30 inclusive.

(3)

The toner for developing an electrostatic latent image according to (1) or (2), wherein,

(4)

The toner for developing an electrostatic latent image according to any one of (1) to (3), wherein,

(5)

(6)

(7)

The toner for developing an electrostatic latent image according to any one of (1) to (6), wherein,

the fatty acid metal salt particles are zinc stearate particles.

(8)

The toner for developing an electrostatic latent image according to any one of (1) to (7), wherein,

the resin particles are crosslinked vinyl resin particles.

(9)

The toner for developing an electrostatic latent image according to any one of (1) to (8), wherein,

the resin particles are styrene (meth) acrylic resin particles.

(10)

The toner for developing an electrostatic latent image according to any one of (1) to (9), further comprising silica particles (B) other than the silica particles (a) externally added to the toner particles.

(11)

The toner for developing an electrostatic latent image according to any one of (1) to (10), further comprising strontium titanate particles externally added to the toner particles.

(12)

The toner for developing an electrostatic latent image according to (11), wherein,

(13)

The toner for developing an electrostatic latent image according to any one of (1) to (12), wherein,

(14)

The toner for developing an electrostatic latent image according to any one of (1) to (13), further comprising silica particles (B) other than the silica particles (A) externally added to the toner particles,

(15)

The toner for developing an electrostatic latent image according to any one of (1) to (14), wherein,

(16)

The toner for developing an electrostatic latent image according to any one of (1) to (15), wherein,

(17)

The toner for developing an electrostatic latent image according to any one of (1) to (16), wherein,

(18)

The toner for developing an electrostatic latent image according to (17), wherein,

the silane coupling agent contains an alkyl trialkoxysilane.

(19)

The toner for developing an electrostatic latent image according to any one of (1) to (18), wherein,

d50 The values of (150) -D1 (150) are less than 1.5,

d50 The value of (90) -D1 (90) is less than 1.0.

(20)

An electrostatic latent image developer containing the toner for electrostatic latent image development described in any one of (1) to (19).

(21)

A toner cartridge containing the toner for electrostatic latent image development described in any one of (1) to (19), and

is attached to and detached from the image forming apparatus.

(22)

A process cartridge is provided with a developing member,

the developing member accommodates (20) the electrostatic latent image developer and develops an electrostatic latent image formed on a surface of an image holding body into a toner image by the electrostatic latent image developer,

(23)

An image forming apparatus includes:

an image holding body;

a charging member that charges a surface of the image holding body;

a developing member that accommodates (20) the electrostatic latent image developer and develops an electrostatic latent image formed on a surface of the image holding body into a toner image by the electrostatic latent image developer;

(24)

An image forming method, comprising:

A charging step of charging the surface of the image holder;

a developing step of developing an electrostatic latent image formed on a surface of the image holder into a toner image with the electrostatic latent image developer described in (20);

According to the invention of (1), (4), (5), (6), (7), (8), (9), (10), (11), (12), (16), (17) or (18), there is provided a method of measuring Net intensity N of molybdenum element by fluorescent X-ray analysis, as compared with the case where the nitrogen element compound containing molybdenum element is added to silica particles having nitrogen element compound which are externally added to toner particles containing binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si When the toner is less than 0.035 or more than 0.45, color streaks are less likely to occur.

According to the invention as recited in (2), there is provided a method of comparing the ratio N _Mo /N _Si When the amount is less than 0.05 or exceeds 0.30, the toner for developing an electrostatic latent image is less likely to cause color streaks.

According to the invention as recited in item (3), there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks when the ratio Dp/Da of the average particle diameter Dp of the resin particles to the average primary particle diameter Da of the silica particles (a) is less than 0.75 or more than 15.

According to the invention as recited in (13), there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the surface coating ratio C1 is less than 10% or more than 60%.

According to the invention as recited in (14), there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the ratio C1/C2 of the surface coating ratio C1 to the surface coating ratio C2 is less than 0.2 or exceeds 1.5.

According to the invention as recited in (15), there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than when the amount of free oil contained in the toner for developing an electrostatic latent image is less than 0.01 mass% or exceeds 0.1 mass%.

According to the invention as recited in the item (19), there is provided a toner for developing an electrostatic latent image which is less likely to cause color streaks than the case where at least one of D1 (90), D50 (90), D1 (150) and D50 (150) is less than 0.5 or exceeds 2.5, the value of D50 (150) -D1 (150) is 1.5 or more, or the value of D50 (90) -D1 (90) is 1.0 or more.

According to the invention as recited in (20), there is provided a method for producing a toner particle comprising a binder resin and resin particles, wherein the method comprises the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method comprising the step of measuring the Net strength N of molybdenum element in silica particles containing nitrogen element compound containing molybdenum element and externally added to toner particles containing the binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of less than 0.035 or more than 0.45, the development of an electrostatic latent image developer which is less likely to produce color streaks.

According to the invention as recited in item (21), there is provided a method of producing a toner containing a binder resin and resin particles by fluorescence, which comprises adding a nitrogen-containing compound containing molybdenum element to silica particles containing a nitrogen-containing compound containing molybdenum elementNet intensity N of molybdenum element measured by X-ray analysis _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of less than 0.035 or more than 0.45, color streaks are not easily generated.

According to the invention as recited in item (22), there is provided a method for producing a toner particle comprising a binder resin and resin particles, wherein the method comprises the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method wherein the method is applied to silica particles comprising a nitrogen-containing compound containing molybdenum element externally added to toner particles comprising a binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of an electrostatic latent image developer of less than 0.035 or more than 0.45, color streaks are less likely to occur.

According to the invention as recited in (23), there is provided a method for producing a toner comprising a binder resin and resin particles, wherein the method comprises the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method wherein the method is applied to silica particles containing nitrogen element compound containing molybdenum element, which are externally added to toner particles containing a binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of the electrostatic latent image developer smaller than 0.035 or exceeding 0.45, color streaks are less likely to occur.

According to the invention as recited in (24), there is provided a method for producing a toner particle comprising a binder resin and resin particles, wherein the method comprises the step of measuring the Net strength N of molybdenum element by fluorescent X-ray analysis, as compared with the method wherein the method is applied to silica particles comprising a nitrogen-containing compound containing molybdenum element externally added to toner particles comprising a binder resin and resin particles _Mo Net strength N with silicon element _Si Ratio N of _Mo /N _Si In the case of an electrostatic latent image developer of less than 0.035 or more than 0.45, color streaks are less likely to occur.

The foregoing embodiments of the invention have been presented for purposes of illustration and description. In addition, the embodiments of the present invention are not all inclusive and exhaustive, and do not limit the invention to the disclosed embodiments. It is evident that various modifications and changes will be apparent to those skilled in the art to which the present invention pertains. The embodiments were chosen and described in order to best explain the principles of the invention and its application. Thus, other persons skilled in the art can understand the present invention by various modifications that are assumed to be optimized for the specific use of the various embodiments. The scope of the invention is defined by the following claims and their equivalents.

Claims

1. A toner for developing an electrostatic latent image, comprising:

toner particles containing a binder resin and resin particles;

fatty acid metal salt particles externally added to the toner particles; and

2. The toner for developing an electrostatic latent image according to claim 1, wherein,

the ratio N of the silica particles (A) _Mo /N _Si Is 0.05 to 0.30 inclusive.

3. The toner for developing an electrostatic latent image according to claim 1 or 2, wherein,

4. The toner for developing an electrostatic latent image according to any one of claims 1 to 3, wherein,

5. The toner for developing an electrostatic latent image according to any one of claims 1 to 3, wherein,

6. The toner for developing an electrostatic latent image according to any one of claims 1 to 3, wherein,

7. The toner for developing an electrostatic latent image according to any one of claims 1 to 6, wherein,

the fatty acid metal salt particles are zinc stearate particles.

8. The toner for developing an electrostatic latent image according to any one of claims 1 to 7, wherein,

the resin particles are crosslinked vinyl resin particles.

9. The toner for developing an electrostatic latent image according to any one of claims 1 to 8, wherein,

the resin particles are styrene (meth) acrylic resin particles.

10. The toner for developing an electrostatic latent image according to any one of claims 1 to 9, further comprising silica particles (B) other than the silica particles (a) externally added to the toner particles.

11. The toner for developing an electrostatic latent image according to any one of claims 1 to 10, further comprising strontium titanate particles externally added to the toner particles.

12. The toner for developing an electrostatic latent image according to claim 11, wherein,

13. The toner for developing an electrostatic latent image according to any one of claims 1 to 12, wherein,

14. The toner for developing an electrostatic latent image according to any one of claims 1 to 13, further comprising silica particles (B) other than the silica particles (a) externally added to the toner particles,

15. The toner for developing an electrostatic latent image according to any one of claims 1 to 14, wherein,

16. The toner for developing an electrostatic latent image according to any one of claims 1 to 15, wherein,

17. The toner for developing an electrostatic latent image according to any one of claims 1 to 16, wherein,

18. The toner for developing an electrostatic latent image according to claim 17, wherein,

the silane coupling agent contains an alkyl trialkoxysilane.

19. The toner for developing an electrostatic latent image according to any one of claims 1 to 18, wherein,

d50 The values of (150) -D1 (150) are less than 1.5,

d50 The value of (90) -D1 (90) is less than 1.0.

20. An electrostatic latent image developer containing the toner for electrostatic latent image development described in any one of claims 1 to 19.

21. A toner cartridge which accommodates the toner for developing an electrostatic latent image according to any one of claims 1 to 19, and

is attached to and detached from the image forming apparatus.

22. A process cartridge is provided with a developing member,

the developing member accommodates the electrostatic latent image developer according to claim 20, and develops the electrostatic latent image formed on the surface of the image-holding body into a toner image by the electrostatic latent image developer,

23. An image forming apparatus includes:

an image holding body;

a charging member that charges a surface of the image holding body;

a developing member that accommodates the electrostatic latent image developer of claim 20 and develops an electrostatic latent image formed on a surface of the image holding body into a toner image by the electrostatic latent image developer;

24. An image forming method, comprising:

a charging step of charging the surface of the image holder;

a developing step of developing an electrostatic latent image formed on a surface of the image holder into a toner image with the electrostatic latent image developer according to claim 20;